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Thread: Arca Rm3di

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    Arca Rm3di

    As I research into which camera system to purchase, some doors close while others open. It's clear that I need to do more reading...

    Which brings me to the RM3Di, are there any users on this forum?

    I would like to hear your views and experiences using this system.

    I like to get in close and use foreground interest in my landscape images which made me realize I am going to need a camera with tilt, unless I focus blend which is quite simple but time consuming so I'm not wishing to go down that path.

    The two cameras I'm seriously considering are the Linhof Techno and more recently, the Arca RM3Di.

    I'm aware of some of the downsides to the Techno but know very little about the RM3Di. Could you please share your experiences using this camera, I would highly appreciate it.

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    Re: Arca Rm3di

    I guess you've seen this intro video? Very informative on how the system is used: An introduction to Arca Swiss R cameras by Rod Klukas on Vimeo

    I also like this Luminous Landscape review video http://vimeo.com/5304769 (note that the reviewers are both dedicated ALPA users)

    I have not used the RM3Di, but while waiting for responses from real users I can present some aspects "good to think about" concerning what the camera is capable of.

    * tilt is built-in to the body which is a great cost saver compared to Cambo and Alpa.
    * tilt is only +/- 5 degrees. For longer lenses/close work (shooting flowers etc) this can be a limitation, but for typical landscape grand scenes its not
    * tilt cannot be made diagonally, only forward/backward or left/right, typically not limiting for grand landscape scenes though, as it is almost always about small tilts forward.
    * compared to the Techno or other view camera the lens mount cost is high, if you want many lenses the lens cost gets higher.
    * if you like to carry around long lenses it can get a bit bulky
    * if you want to make pano stitches I prefer a sliding back with click-stops (Techno) rather than gear-turning on the back (RM3Di) as it can be a bit slow
    * while the primary operation of the camera is with a viewfinder and thus approximate framing, some do use ground glass for framing, and the rotaslide sliding back can be used if you want to (I've got conflicting info if it's compatible with infinity focusing or not though, I think it is but needs double-check).

    I'm a Techno user myself and of course hope that you would choose that instead ;-). Concerning pancake cameras RM3Di would have been the number one alternative though, due to the integrated tilt and high precision focusing, and possibility to extend the system to include an MF-two view camera for greater movement flexibility if would need it.

    Movement comparison:
    RM3Di: Back Vertical Rise/Fall 30/20mm, Back Lateral Shift +/- 15mm. Tilt +/-5 degrees. Camera can be mounted on the side or upside down to change vertical shift and tilt direction.

    Techno: back vertical shift +/-20mm, front rise +20mm, Back lateral shift fixed click-stop on sliding back only -17/0/+17mm, Front lateral shift +/-10mm. Tilt +/-10 degress, Swing +/-10 degrees.

    The Techno advantages are best shown if you use many focal lengths including longer ones and often use tilt, and if you would use the ground glass regardless of camera. If you work mostly/only with wides, dislike the ground glass then RM3Di is best. If you shoot at f/8 or f/5.6 often you will love the focusing precision of the RM3Di, if you shoot at f/11 my experience is that the ground glass focusing precision is adequate, but I need a 20x loupe to be satisfied (most only use 6x - 10x)
    Last edited by torger; 26th March 2013 at 06:24.

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    Re: Arca Rm3di

    I use techno with my IQ180 and before that I had the P45+. Focusing using ground glass that came with my sliding back with P45+ was never an issue. But on a 80MP back, I almost always double check focus using live view. Before I got comfortable with the live view, I had more than once wanted to go with the Arca RM3Di. However, the sliding back stitching and the composing using the ground glass are so smooth and quick, I've abandoned the idea. Techno is low tech in comparing to the e-module cloud, but coming from 4x5 view camera, I felt at home after a short period of time.

    I think at the end of the day, you have to ask yourself which workflow you like to work with.

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    Re: Arca Rm3di

    Wow!

    Thank you, Torger.

    This is the type of response I was looking for. I have made enquiries with a few dealers about both cameras with regards to pricing, lenses, etc and must admit, probably to your disappointment () that I am swaying in the direction of the RM3Di.

    I am awaiting an email from a dealer at the moment and will make my final decision soon. Either way (Techno or RM3Di) I'm really looking forward to getting out there with the new setup.

    I have done so much reading over the last week that I now feel confident with my final choices, that said... I would really love to hear from other people before taking the plunge :-)

    I'm going to watch the LL review you linked, many thanks!

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    Re: Arca Rm3di

    Yat,

    Thanks for your view, I must say I am a little intimidated by the idea of using the ground glass to focus as I'm going to be using (most likely) a phase one P45+ back and assume the LCD on that back is not good enough to assess critical focus after the image is captured.

    Am I right in thinking the RM3Di takes away those fears as you can effectively shim the back with the helical focus and note down the adjustments required for the cam/back combination?

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    Re: Arca Rm3di

    I guess you've seen my lengthy Linhof Techno review Review: Linhof Techno . I'd like to update it now when a new ground glass has arrived, but I have not bought it myself yet. It won't change focusing precision though, just make framing of wide angles simpler, possibly tilt-refinement (when you look at the sides of the glass) may be better. An eye-opener for me was that using a 20x loupe gave me significant precision advantage compared to the typical recommendations, but as it is an element of skill your mileage will vary. Despite the advantage I think I'm pretty alone using this high magnification. Before assuming that gg focusing is not precise enough I think one should have tried a high magnification loupe.

    A typical way to use the RM3Di focusing is to have a Lecia Disto D5 (laser distance meter) and a hyperfocal table, for all distances closer than hyperfocal use the D5 to measure and set the distance on the helical focus, the rest hyperfocal or infinity. When you tilt I think most use only tables with RM3Di, i e set forward tilt so the hinge line is at the ground, and then set hyperfocal distance from table to get the typical upper half DoF wedge.

    If you want more fine-tuned tilts you're back to looking at the ground glass, or having a very granular table or tilt dof app, using the disto to take out angles etc; maybe an RM3Di user could explain their tilt workflow. I'd be interested in knowing the details too.

    As long as you can calculate/measure the focus setting you need for the RM3Di you can precisely set it, so yes it takes away some of the insecurity feel you can get with GG focusing.

    I was also choosing between the Techno and the RM3Di. The reason the Techno is better suited for me is that 1) better economy on the lenses as I want many of them, 2) I like to also have longer lenses and then it is less bulk. 3) I don't really like the viewfinder concept so I would be using ground glass anyway. I also appreciate that the Techno provides flexible tilt/swing, I like to have that in the arsenal, but to be truthful I rarely use it. If I'd shoot more flowers and stuff like that I'd use it more, but I don't do that very often. 90% of the time the tilt is forward and in the 1-2 degrees.

    The ground glass I find more as an interesting challenge than being frustrating, and now I think it's quite nice to be in the exclusive "view camera user group" ;-). I see it from the bright side -- using the ground glass is a part of the low-tech fun using a technical camera :-). However, when digital backs have as good live view as DSLRs I'll surely ditch the sliding back and focus directly on the back. I think that's a few years away though, especially for me that use older generation backs for better economy.

    I'd say though that the RM3Di is a safer buy for sure if you have to buy without testing. It's more user-friendly, and focusing precision can not disappoint. The ground glass makes the Techno require some eyesight capability and focusing skill, and it also requires from the photographer to have a bit relaxed relation to focus placement precision, ie even with the best skill you cannot achieve same precision you can with a RM3Di and a laser distance meter. I'd say that for practical landscape image making the GG focus placement precision skilfully made does not jeopardise image quality (i e it will not be better with an RM3Di), but not all you ask will give you that answer. So it's personal. With the RM3Di noone will tell you that focusing precision will disappoint. Some may think it is a bit overkill though, there's a lot of turning on that helical focusing ring.

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    Re: Arca Rm3di

    Actually, I never really felt the need to check focus on my P45+ using the ground glass. I was 95%+ confident in focusing with GG even with tilt and shift involved and I was only using a 4-6X loupe.

    Yes, RM3Di will essentially like a manual focus with a DSLR, I believe the RM3Di helical can be adjusted unlike the requirement of shimming on an Alpa. I doubt you need to do much adjustment out of the box assuming your P45+ is calibrated properly. However, I have not used one to confirm this.

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    Re: Arca Rm3di

    Having used both cameras it's a difficult decision. Bottom line, they're both tremendous bits of kit.

    What I would say is try them both if you can - viewfinder composition on the RM3D/i (if you don't use the ground glass) is not everyone's cup of tea, especially if you're a landscape shooter using graduated filters. Then it becomes a shoot-check-adjust filter-shoot-check-adjust filter routine. With a G/G (on the Techno or RM3D/i) you can see exactly the effect of the filter and any tilts/swings you've got. A couple of architectural photographers I've met use the RM3D - they focus with the distance scales provided, compose on the ground glass and check everything by tethering. The rationale being why spend megabucks on a set up and then 'approximately' compose through a viewfinder. Personally, I hate all viewfinders. Folks say they speed up shooting - but to be honest, why even consider an RM3D/i or Techno if speed is an issue. Stick with a DSLR.

    What else? Dealer support. With the Techno, in the UK you have Paula at Linhof and Studio behind you to answer any questions you have or from which to source any bits and pieces you need. Linhof are a speedy company in my experience, and the range of accessories available for the Techno (any Technika fitting on the front and anything that fits the M679 on the rear) is huge. Robert White used to carry all the A/S large format gear, but those days have pretty much gone, even though they can still source it. Digital SLRs and 4/3 are where they are at these days. That leaves you with Peartree or Teamwork in London - they both list A/S gear. Remember, A/S is not a speedy company to deal with in general - if you break something be prepared to wait on any repair or replacement if your dealer doesn't have one in stock (unlikely).

    If you see yourself using a variety of lenses, or wanting to shoot, say, still life or macro as well as landscape, without having to buy additional bits and pieces of kit then the Techno is hands down the clear winner. If you need simultaneous swing and tilt, then again the Techno has the advantage. By combining rear rise/fall with front rise/fall you can actually reach +/- 20mm/40mm with the Techno. Equally, by combining front shift with rear shift, you can reach +/- 27mm. That's more than the RL3D, let alone the RM3D/i. The proprietary mounts of A/S are expensive, even though they don't need a helical, probably adding $1200 per lens to the cost. Whilst there are a fair few RM3D/i users out there, selling a used lens isn't as straightforward as sticking your Canon 35/2.8 on eBay, so once you invest in glass be prepared to stick with it. In comparison, lensboards for the Techno are inexpensive, and if you want to experiment with pinholes or old petzval lenses, it's easily done.

    Shimming on the RM3D/i simply involves A/S figuring out how much they need to adjust the focussing mechanism on the camera so that the numbers they print for focussing match with your back. This requires that you send your DB/RM3D/i to them, and of course if you change DB then it needs recalibrating. Better to figure this out yourself in terms of an 'offset' and adjust focus accordingly (i.e. reprint their focus cards with your offset included).

    Finally, have one eye on the future. CMOS MFDBs are probably less than two years away - then the issue of this or that focussing system goes straight out of the window. Imagine Live View with Live Focus Mask - er, yes please.

    Jim

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    Re: Arca Rm3di

    Quote Originally Posted by f8orbust View Post
    Shimming on the RM3D/i simply involves A/S figuring out how much they need to adjust the focussing mechanism on the camera so that the numbers they print for focussing match with your back. This requires that you send your DB/RM3D/i to them, and of course if you change DB then it needs recalibrating. Better to figure this out yourself in terms of an 'offset' and adjust focus accordingly (i.e. reprint their focus cards with your offset included).
    Almost all of our Arca Swiss customers have done this calibration themselves, or had us as a dealer do it for them. I only know of one user who has sent their entire system to Arca for calibration which strikes me as entirely unnecessary. It takes <20 min the first time you do it and <10 min there after.

    You can either print new cards or simply remember to add your offset any time you look at the card. The later strategy is especially nice when dealing with IR or UV photography since you can determine a fixed spectral focus shift and apply it without the need for separate focusing.

    It's one of those things that sounds potentially complicated when you are first exposed to it, and then becomes very natural and fast when you've done it a few times.
    Doug Peterson , Digital Transitions | Email
    Dealer for: Phase One, Mamiya Leaf, Arca-Swiss, Cambo, Eizo, Profoto
    Office: 877.367.8537. Cell: 740.707.2183

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    Re: Arca Rm3di

    Torger's comments are right on. A few other things: the A/S gear is very sensible, and lovely piece of kit, but add up the weight of the whole system, and its not necessarily light. The Techno, surprisingly, is quite small and with simple lenses, rather light weight. I find it more easily carried about in a pack than MFDB gear with its larger and heavier lenses.

    If you shoot f11-16, and more landscape than closeup, focusing issues really do go away. Use of the Techno is quite simple and old-school, an update of the traditional view camera. The movement selection is quite broad - the only issue being that front shift is limited. So horiz. stitching is best done with a stitching back, which gives great compositional flexibility and allows a 55 mm lens to work (in 2-3 shots) more like a 35. Vertical rise and fall is generous (+/- 20mm) on the back. All rather clever.

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    Re: Arca Rm3di

    I am a huge fan of the Rm3di.
    Focusing is stupid simple. I did not have to send my DB out for calibration with my technical camera. The rotations on the helical focusing rings are color coded to the settings (per distance-I use the Leica DS-5) on the card supplied (for each individual lens) by Arca. Arca has recently updated the numbers on the card and they are dead on accurate.
    In a few days I will receive the E Module which I am led to believe will eliminate the need for the card.
    Because the tilt is in the body, every lens is a tilt shift. I have five lenses-32 rodie-43 Schneider-72 Schneider-120 Schneider-and the 210 Schneider.
    Using (per Doug Peterson) a rule of thumb---- 1 degree of tilt for every 32 degrees of focal length, I find that focus stacking is almost never necessary'
    The viewfinder on the Arca is relatively useless which is the case (I am led to believe) on all technical cameras. I rely on my LCD to check my composition.
    The Arca Rm3di allows sufficient shift and rise and fall to maximize the use of any of the lenses that I am using.
    The exciting part of the Technical camera to me is the detail provided by the Rodenstock and Schneider lenses. Of course my photography friends think that I am ridiculously anal and perhaps they are correct

    Stanley

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    Re: Arca Rm3di

    Quote Originally Posted by stngoldberg View Post
    I am a huge fan of the Rm3di.
    Focusing is stupid simple. I did not have to send my DB out for calibration with my technical camera. The rotations on the helical focusing rings are color coded to the settings (per distance-I use the Leica DS-5) on the card supplied (for each individual lens) by Arca. Arca has recently updated the numbers on the card and they are dead on accurate.
    In a few days I will receive the E Module which I am led to believe will eliminate the need for the card.
    Because the tilt is in the body, every lens is a tilt shift. I have five lenses-32 rodie-43 Schneider-72 Schneider-120 Schneider-and the 210 Schneider.
    Using (per Doug Peterson) a rule of thumb---- 1 degree of tilt for every 32 degrees of focal length, I find that focus stacking is almost never necessary'
    The viewfinder on the Arca is relatively useless which is the case (I am led to believe) on all technical cameras. I rely on my LCD to check my composition.
    The Arca Rm3di allows sufficient shift and rise and fall to maximize the use of any of the lenses that I am using.
    The exciting part of the Technical camera to me is the detail provided by the Rodenstock and Schneider lenses. Of course my photography friends think that I am ridiculously anal and perhaps they are correct

    Stanley
    Stanley:

    What do you mean by "1 degree of tilt for every 32 degrees of focal length"? It sounds interesting and new to me. Would you please tell me more about it? Thanks!

    Michael

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    Re: Arca Rm3di

    Would love to see a picture of the RM3D/i with the 210mm - must look like a tank barrel

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    Re: Arca Rm3di

    I've had mine for about 18 months. It is exceptionally precise and works great; that precision comes at the expense of being a little slower to focus. I also have used the Cambo system, and like it too; and while faster in many respects, the lesser level of precision renders it a bit more "Zen" to the focus and set movements. I can make a great argument in favor of either, and would own both if lensmounts were compatible (seriously, I would!)
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    Re: Arca Rm3di

    I have the RM3Di and Factum. Love both for the precision and the idiot-proof focusing. I recently got some goodies including the eModule Cloud and Factum grip, all of which make using the whole kit an even better experience. The ability to mix and match components is also a bonus.

    On the downside, these guys are a bunch of techies, so don't expect and fluffy service, marketing collateral, manuals etc.

    If you are willing to wait for the various bits to trickle in, then you will get a high-quality system that works first time out of the box, is very precise, and will likely be something you keep for a very long time.

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    Re: Arca Rm3di

    "1 degree of tilt for every 32 degrees of focal length", I assume it's "for every 32mm of focal length".

    That is 1 degree for the 32mm, 1.3 for the 43mm, 2.3 for the 72mm, 3.8 for the 120mm and so on. This rule of thumb seems to be that if the camera is mounted at eye level over the ground, the hinge distance will be approximately down to the ground level (~1.8 meters), and if you then set the focus distance on hyperfocal you'll have a DoF wedge whose far edge goes horizontally out.

    Have I understood the process correctly?

    While it is a bit approximate way to work, it will give good results in many typical landscape scenarios. But what do you do if the camera is mounted at a different height or the ground is sloping, and/or there's some tree so it's better to aim the focal plane a bit higher or lower? I guess you fallback to the ground glass then, or just skip tilting and do focus stacking or let some parts be out of focus?

    With the Techno my typical tilt workflow is as follows: I use a table to set a scheimpflug/hinge distance as starting point after estimating the distance I need. On a wide angle it's hard to look at the edges on the GG (you need to tilt the loupe, which is not possible with my 20x, but I have a 10x I can do that with) which you typically need to do if you want to verify that tilt brings foreground into focus, I rarely do that. I use my table that is made in 0.5 degree steps for all my focal lengths (one could have a DoF app in the phone too, but I prefer a printed table on a card), I set a tilt from that sometimes in-between settenings (ie not always an even 0.5 degree step) and then I set the direction on the focal plane by aiming at the vertical center of the tallest feature (which means that often focus setting is closer than hyperfocal distance). Shoot, and verify at key points that all is sharp with 100% view on the back. With longer focal lengths and larger tilts I verify also the tilt on the ground glass. It shall be interesting to test Linhof's new bright ground glass and see how much better at edge looking it is. The required f-stop I also use a table to find out, by looking at DoF height at infinity and estimating from that. In difficult corner cases it's nice to verify using 100% view on the back.

    For longer lenses it is quite typical that one have to make some fine-tuned compromise, ie not everything can be perfectly in focus, and in that case it's nice to look at the ground glass also for fine-tuning tilt. For closeup work the GG for tilt/swing setting is a necessity of course.

    As I've understood it, a view camera user typically puts more value into tilt/swing than a pancake camera user does. It depends on the shooting style how much you will appreciate the feature.

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    Re: Arca Rm3di

    A year ago I thought CMOS backs was far far away, possibly never coming. Now it seems that CMOS backs actually is showing on the horizon, so maybe we have one within 2 years. With a digital back with a DSLR-like live-view I think the the ultra-precise focusing mount of the RM3Di will lose some of its attraction, and many will prefer a faster mount like on the Cambo and just use live view for focusing instead. The view camera will also be attractive to a much wide audience with a liveview-capable back as you don't need to use the ground glass or sliding back in that case.

    If one plans to have the system for many years it may be worthwhile to have this in mind.

    On the other hand, when setting hyperfocal distance (when you don't focus at a specific object) it's nice to have a high precision helicon mount.

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    Re: Arca Rm3di

    Oh, one more thing; when focusing on ground glass or a future liveview, one uses a rocking motion to find the peak focus. For this to work well the focusing must not be too finely threaded, i e if you need to turn a long way to bring the object significantly out of focus it will be harder to rock-and-peak.

    I have not tested the RM3Di, so one of the first things I would test is if it is feasible to focus on the GG without using the distance scale. If it's really finely threaded I would suspect that it's not really feasible, and then it the camera won't be that useful for liveview focusing when that eventually becomes available. For me that would be a big minus if I intended to keep the camera for a long time. Of course you can always use the "e-module Cloud" to focus optically, but it would be a bit boring having to use such an accessory if having a working liveview on the back.

    Jack who has used both Cambo and RM3Di maybe can comment on this?

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    Re: Arca Rm3di

    I'm not sure the very precise helical of the arca will be an issue with LV, quite the contrary actually.
    When manually focussing lenses on the D800 in live view, I keep dreaming of a much longer, finer focus ring.

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    Re: Arca Rm3di

    In another thread on this forum I found that the RM3Di has 7 um movement for 1 degree turn, for all lenses. (As depth of focus is constant regardless of focal length we don't need to take focal length into account here.)

    The Techno rail has 42 um movement for 1 degree turn.

    The Alpa has 27.8 um for Schneider lenses and 33.3 um for Rodenstock lenses, and Cambo something similar as the HPF rings are compatible as far as I know.

    I don't know what a typical D800 lens has, but it seems ALPA has 270 degrees of turning range, and a DSLR autofocus lens often has something like 90-120 degrees of turning, assuming similar near limit the travel would be 100 um per degree.

    My own take on the ideal threading for precise manual focusing via live view is ~20-30um per degree (i e I'd prefer a bit finer threading than the Techno has, but not much), i e the Alpa is spot on, the Techno a bit high, DSLR auto lenses very high, and the RM3Di is, well, very finely threaded indeed.

    As tech cam lenses is f/5.6 or f/4 at best the peaking is quite soft (compared to a f/1.4 DSLR lens for example), so I think one should not have too finely threaded to make it user-friendly. But I cannot say anything about ground glass focusing experience on the RM3Di as I haven't had the opportunity to try focus with it.

    The tilt has "normal" sensitivity as far as I know, but it also seems like when tilt is involved the default way to work is to use approximate methods, i e set a tilt from a table and set hyperfocal distance and that's it. If you want some other type of tilt so you'd want to have a typical tilt-focusing workflow on the ground-glass (or future liveview) I would suspect that the normal-threaded tilt and very fine focus will feel a bit awkward. If I had an RM3Di I would probably make my own tilt table which also takes alternate focal plane directions into account, so I can aim it in other directions than the hyperfocal way (ie far edge straight out), I haven't heard of any RM3Di user having such tables, but maybe there are?

    If you think flexible tilt will be an important feature for your shooting style it may be worthwhile to think this over a bit more. The Cambo tilt lens mount allows for diagonal tilts (ie tilt+swing in view camera terms as the Techno) as does some DSLR tilt-shift lenses (eg Canon's version II TS-E lenses), but the RM3Di does not.
    Last edited by torger; 27th March 2013 at 04:33.

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    Re: Arca Rm3di

    Agreed on all you said, you've studied the topic a lot more than I have.

    I guess my feeling is I doubt LV will deprecate the use of very fine helicals and favor "faster mounts". For instance the RS40 has 360 to go from infinity to 0.9m on the rm3d, it's not *that* insanely precise.
    Since I don't shoot landscapes tilt is not something I use a lot. Focus stacking is more useful with high MP backs in architecture, a process where very precise focusing is welcome, whether with LV or not.

    Now if that's suitable for landscape work or the OP needs is another matter, indeed.

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    Re: Arca Rm3di

    Some really interesting comparisons have been made here, one point regarding tilt and focusing at the hyperfocal distance...

    I'm not sure approximations with tilt using printed tables will provide optimal results, particularly with high resolution digital sensors. When I was using the D3x with the PC-E lenses and live view, I noticed a big difference when tilt was slightly out, so much so that I have a handful of images that I have not made available as prints on my website.

    Regarding setting the lens focus at the hyperfocal distance, this will set the angle of the focal plane when tilt is applied so why would one set the lens at the hyperfocal distance? Am I right in assuming some of you are doing this as a starting base?

    Lets assume we set the camera up to take an image of a sweeping view with no vertical subject matter, the land fairly flat with a mountain in the distance. Assuming the camera is approx 5-6 feet from the ground and set the tilt to 1 degree to bring the foreground into focus. If you have the lens set to hyperfocal distance, aren't you going to be throwing away a certain degree of depth of field due the the angle of the focal plane being to steep? By adjusting the focus nearer to infinity, you would be adjusting the focal plane to better suit the typical scene described.

    I think regardless of which of the two cameras (techno & rm3di) is used, tilt will need to be set using the ground glass for precision, which one would be better would come down to the ground glass on each camera, loupe used and one's eyesight. This is were I think live view would be a welcome feature for these tech cams.

    That been said, doesn't the IQ back's have this feature now? or is the refresh rate still too slow?

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    Re: Arca Rm3di

    Quote Originally Posted by JGR View Post
    Regarding setting the lens focus at the hyperfocal distance, this will set the angle of the focal plane when tilt is applied so why would one set the lens at the hyperfocal distance? Am I right in assuming some of you are doing this as a starting base?

    Lets assume we set the camera up to take an image of a sweeping view with no vertical subject matter, the land fairly flat with a mountain in the distance. Assuming the camera is approx 5-6 feet from the ground and set the tilt to 1 degree to bring the foreground into focus. If you have the lens set to hyperfocal distance, aren't you going to be throwing away a certain degree of depth of field due the the angle of the focal plane being to steep? By adjusting the focus nearer to infinity, you would be adjusting the focal plane to better suit the typical scene described.

    I think regardless of which of the two cameras (techno & rm3di) is used, tilt will need to be set using the ground glass for precision, which one would be better would come down to the ground glass on each camera, loupe used and one's eyesight. This is were I think live view would be a welcome feature for these tech cams.

    That been said, doesn't the IQ back's have this feature now? or is the refresh rate still too slow?
    I've attached an image showing what happens with the wedge if you focus at hyperfocal distance. It's ideal for scenes with horizontal ground and covering as much height as possible. But as you say, if you don't have anything high objects close-by it's usually better to aim the focal plane straight at the horizon. This is also easy to do with an RM3Di, just set the focus at infinity and you aim (approximately) at the horizon. To have some alternatives in-between one could make a table or use a tilt DoF app, so you could use your Leica Disto to aim and find an angle, and check in the table which focus distance you should use for that angle and tilt combination. The problem with these inbetween angles is that unlike hyperfocal/infinity the focus plane angle will depend also on the amount of tilt used (ie when you change tilt, you need to change focus distance to keep same focus plane angle), so a table would be messy. Maybe a DoF app with tilt support is the way to go.

    Depending on the shape of the foreground you can make all sorts of of interesting compromises. The messy/impossible forest scene I've attached I shot with a 90mm at about 4 degree tilt f/22, also tried to focus stack it (which worked) but I liked the tilted one-shot image better despite that resolution suffers a bit from diffraction. In this case I chose to set the focus plane along the log going out in the right corner and aim it a bit high, the water below is slightly out of focus but I think it gives a nice 3D feel to it.

    One thing you can do with a the Techno and other view cameras which you can't(?) with RM3Di is that you can actually aim the focus plane downwards even with forward tilt. Not that you need to use it often, but you can . The thing is that in order to do so you need to move the lens *closer* than the infinity setting.

    The IQ liveview is like the ground glass -- some say it's perfectly useful and they use it all the time, and some say it's next to useless. I have not used it myself so I don't know what I would think. The problems are the usual, slow refresh rate, requires ND filters in bright light, and too noisy in poor light. (The best liveview is made by Canon I think, considerably smoother than Nikon's.)

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    Re: Arca Rm3di

    Once you start tilting the lens, focus effectively becomes the means for changing the angle of the plane of focus about the hinge line, thus I've never really subscribed to talking about 'hyperfocal distance' when tiliting the lens - unless what is meant is the focus distance that maximises the depth of field 'wedge'. Typically, the most simple implementation is to focus at infinity, tilt the lens so the hinge line is at your feet and then the plane of focus will be parallel to the ground. However, this means you're losing out on the dof behind the plane of focus. It's better to have the plane of focus angled up in order that the far limit of the dof behind the plane of focus is just in the ground (I guess whatever this distance is could be called the 'hyperfocal' distance). For instance, using a 35mm lens on a DB with a CoC of 0.003mm, with the lens 120cm off the ground and shooting @f11, focussing at about 3m and adding a forward tilt of 1.7 degrees will put the hinge line at your feet and the far limit of the dof just into the ground, with the near limit at about 40 degrees to the horizontal. The actual plane of focus will be at about 22 degrees to the horizontal. It all sounds a bit hellish, but in practice focus at about 3m and tilt the lens 1.5 degrees and you should be good. Focus too far and the plane of focus will be shallower (further edge of the dof deeper in the ground); focus too close and the plane of focus will be steeper (further edge of the dof above the ground). So, if in doubt, focus a little bit too far away.

    Tilts/swings done on the fly (i.e. with no chart of presets to hand) really need to be observed, so you need to shoot tethered or use a ground glass to see exactly what's going on, especially in systems where you're going to possibly need to refocus as well, since you're effecting a base tilt (e.g. long lenses on pancake cameras). Given the size of todays average ground glass, this takes a good loupe. The new Linhof and Studio / Silvestri one, 12x with a square base (for getting into the corners) is perfect. If you use an IQ back then you also have live view as an option, or you could use the shoot-check-adjust-shoot-check-adjust routine. I find a ground glass infinitely more satisfying than the shoot-check-adjust routine.

    In terms of setting fractions of a degree, I found the Techno to be easier than the RM3d/i, simply because the gearing is finer. The current set of Alpa T/S adapters allow the finest setting of T/S, but unfortunately are limited to only certain lenses.

    Disclaimer: Throughout all this, I have assumed the sensor plane is vertical and the ground plane is perpendicular to it.
    Last edited by f8orbust; 27th March 2013 at 07:18.

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    Re: Arca Rm3di

    Because each lens only uses a 'range' of the throw of the helical on the RM3D/i, it is actually possible to bring a lens closer than it's infinity position.

    The RM3D/i has clearly been designed as a camera on which it is possible to repeatedly set certain distances with greater accuracy than any other tech camera. In this it excels. However, what you gain on the swings you lose on the roundabouts, and because the helical pitch is so fine, you lose the ability to 'pop' areas of the image in and out of focus quickly - which is what you need to do to initially find focus on the groundglass. I found trying to move the focus ring quickly enough to achieve this impossible. It was designed to be used with a table of distances, and this is how it operates the best. Just don't leave them at home.

    This also affects tilts done on the fly, as once I've set a tilt I like to move the angle of the plane of focus fairly quickly (initially) so my eye can pick it up and see where it is and what it's doing.

    If I was an RM3D/i landscape shooter, I would probably have a chart of tilts prepared, for certain focus distances and lens heights. These would do for, maybe, 75% of the situations encountered. For 100% - and as a landscape shooter specifically - I still think you need to be able to use the groundglass and snap focus quickly. The groundglass that was on the RM3D/i I used was 'ok' but nowhere near the newer Linhof or Alpa ones - it would be one of the first things I would replace.
    Last edited by f8orbust; 27th March 2013 at 07:19.

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    Re: Arca Rm3di

    Quote Originally Posted by Frederic View Post
    Focus stacking is more useful with high MP backs in architecture, a process where very precise focusing is welcome, whether with LV or not.
    If one wants to use focus stacking the helical focusing is indeed nice.

    I've done focus stacking with the Techno, and it works but is kind of hackish. What you do is that you tape a ruler to the base, find the starting and end-point of your scene, note where on the ruler it is, and then shot at f/16 and move 0.5mm between each shot. It works well, but with close foreground it can be many shots. For f/11 one have to reduce movement to about 0.3mm between shots and for that I'd like to have some special ruler with 1/3 mm markings.

    As far as I've understood most that do focus stacking with an RM3Di rather than covering the whole range they pick out some important foreground object and some important background object and snap a picture for those, and let stuff inbetween be a bit out of focus. The problem is that if you want to cover the whole range you may quickly end up having to shot 10+ pictures for one scene. In a scene where you have a tree up close, then a stretch of water, and then some background on a distance this two-shot focus stack will work very well. In an unbroken line of landscape it may not work so well. This type of stacking can be done on a Techno too but is not very practical, as you'd have to slide in the glass and refocus to take the next shot, which is a bit slow and there's a high risk of disturbing the camera.

    Stacked scenes rarely is rarely free from artifacts (due to focus-breathing, defocus shadowing caused by close objects, movements by wind etc) either, and to me I rather make a slightly diffraction-suffering image (smaller f-stop) and/or a tilt "compromise" than risk having multi-shot artifacts. From an artistic standpoint I also like the concept of capturing the scene in one exposure.

    But again, it depends on shooting style, some prefer stacking ahead of tilt also in landscape.

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    Re: Arca Rm3di

    Quote Originally Posted by f8orbust View Post
    Because each lens only uses a 'range' of the throw of the helical on the RM3D/i, it is actually possible to bring a lens closer than it's infinity position.

    The RM3D/i has clearly been designed as a camera on which it is possible to repeatedly set certain distances with greater accuracy than any other tech camera. In this it excels. However, what you gain on the swings you lose on the roundabouts, and because the helical pitch is so fine, you lose the ability to 'pop' areas of the image in and out of focus quickly - which is what you need to do to initially find focus on the groundglass. I found trying to move the focus ring quickly enough to achieve this impossible. It was designed to be used with a table of distances, and this is how it operates the best. Just don't leave them at home.

    This also affects tilts done on the fly, as once I've set a tilt I like to move the angle of the plane of focus fairly quickly (initially) so my eye can pick it up and see where it is and what it's doing.

    If I was an RM3D/i landscape shooter, I would probably have a chart of tilts prepared, for certain focus distances and lens heights. These would do for, maybe, 75% of the situations encountered. For 100% - and as a landscape shooter specifically - I still think you need to be able to use the groundglass and snap focus quickly. The groundglass that was on the RM3D/i I used was 'ok' but nowhere near the newer Linhof or Alpa ones - it would be one of the first things I would replace.
    Since I am more than 55 years away from my last physics course, I tend to take a less technical approach to get the best focus.
    1. I laser measure the midpoint distance of the area I want to maximize focus and coordinate my helical ring to the number on the chart supplied by Arca
    2. Tilt my lens 1 degree per every 32 mm of focal length of my lens
    3. Set my aperture to f8
    4. Take an image and check focus on LCD in the critical areas of the image (when I am indoors I prefer to tether to my computer using Phocus) Those of you to have a phase one IQ DB have it ready made with the focus mask-I envy you
    5. Usually I find focus fine at this point, but occasionally I find that f11 is necessary and I once had to use f16
    For a 73 year old grandfather of six this avoids the hinge line and all the other jargon which I don't choose to master at this point in my life
    Stanley

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    Re: Arca Rm3di

    Quote Originally Posted by stngoldberg View Post
    Since I am more than 55 years away from my last physics course, I tend to take a less technical approach to get the best focus.
    1. I laser measure the midpoint distance of the area I want to maximize focus and coordinate my helical ring to the number on the chart supplied by Arca
    2. Tilt my lens 1 degree per every 32 mm of focal length of my lens
    3. Set my aperture to f8
    4. Take an image and check focus on LCD in the critical areas of the image (when I am indoors I prefer to tether to my computer using Phocus) Those of you to have a phase one IQ DB have it ready made with the focus mask-I envy you
    5. Usually I find focus fine at this point, but occasionally I find that f11 is necessary and I once had to use f16
    I understand the tilt part, it brings hinge line approximately to the ground for eye-level tripod height, but the way to set focus distance seems to me that it would cause a quite random result. After tilting the focus distance + tilt angle in combination decides the angle of the focus plane which may not have anything to do with maximizing sharpness at the original focus distance.

    However, if you often shoot wide angle that first chosen focus distance will probably often be past the hyperfocal distance and then the focus plane angle quite slowly lowers towards straight out at infinity, so it will work quite okay. But, if focus distance happens to be shorter than the hyperfocal distance it is likely that the focus plane shoots off into the sky.

    A more repeatable method would be to always focus at infinity when tilting, or hyperfocal. "Hyperfocal" is a bit controversial though as it depends on the circle of confusion, and a suitable size of that in the digital world is something many of us like to discuss . (The distant horizon is put at the edge of the DoF with a hyperfocal tilt-wedge and that may not be what you want if you actually see distant horizon)

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    Re: Arca Rm3di

    Quote Originally Posted by torger View Post
    I guess you've seen this intro video? Very informative on how the system is used: An introduction to Arca Swiss R cameras by Rod Klukas on Vimeo

    I also like this Luminous Landscape review video Arca Swiss Rm3d Review on Vimeo (note that the reviewers are both dedicated ALPA users)

    I have not used the RM3Di, but while waiting for responses from real users I can present some aspects "good to think about" concerning what the camera is capable of.

    * tilt is built-in to the body which is a great cost saver compared to Cambo and Alpa.
    * tilt is only +/- 5 degrees. For longer lenses/close work (shooting flowers etc) this can be a limitation, but for typical landscape grand scenes its not
    * tilt cannot be made diagonally, only forward/backward or left/right, typically not limiting for grand landscape scenes though, as it is almost always about small tilts forward.
    * compared to the Techno or other view camera the lens mount cost is high, if you want many lenses the lens cost gets higher.
    * if you like to carry around long lenses it can get a bit bulky
    * if you want to make pano stitches I prefer a sliding back with click-stops (Techno) rather than gear-turning on the back (RM3Di) as it can be a bit slow
    * while the primary operation of the camera is with a viewfinder and thus approximate framing, some do use ground glass for framing, and the rotaslide sliding back can be used if you want to (I've got conflicting info if it's compatible with infinity focusing or not though, I think it is but needs double-check).

    I'm a Techno user myself and of course hope that you would choose that instead ;-). Concerning pancake cameras RM3Di would have been the number one alternative though, due to the integrated tilt and high precision focusing, and possibility to extend the system to include an MF-two view camera for greater movement flexibility if would need it.

    Movement comparison:
    RM3Di: Back Vertical Rise/Fall 30/20mm, Back Lateral Shift +/- 15mm. Tilt +/-5 degrees. Camera can be mounted on the side or upside down to change vertical shift and tilt direction.

    Techno: back vertical shift +/-20mm, front rise +20mm, Back lateral shift fixed click-stop on sliding back only -17/0/+17mm, Front lateral shift +/-10mm. Tilt +/-10 degress, Swing +/-10 degrees.

    The Techno advantages are best shown if you use many focal lengths including longer ones and often use tilt, and if you would use the ground glass regardless of camera. If you work mostly/only with wides, dislike the ground glass then RM3Di is best. If you shoot at f/8 or f/5.6 often you will love the focusing precision of the RM3Di, if you shoot at f/11 my experience is that the ground glass focusing precision is adequate, but I need a 20x loupe to be satisfied (most only use 6x - 10x)
    I am sure you know what you are doing, but a 20x loupe creates more focus problems than it solves as it magnifies the glass pattern so much it can interfere with the image you are trying to focus.
    With standard to longs it may be OK, but with wides I believe it becomes a liability. But if you feel it works for you, then stick with it.
    That is why most stay below 7x for a magnifier.
    Rod
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    R-Line Technical Cameras, Large Format View Cameras, Tripod Heads D4, D4m, P1, P0, Z1, Z2, C1 Cube.
    http://www.rodklukas.com/arca-swiss 480-755-3364
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    Re: Arca Rm3di

    Quote Originally Posted by f8orbust View Post
    Once you start tilting the lens, focus effectively becomes the means for changing the angle of the plane of focus about the hinge line, thus I've never really subscribed to talking about 'hyperfocal distance' when tiliting the lens - unless what is meant is the focus distance that maximises the depth of field 'wedge'. Typically, the most simple implementation is to focus at infinity, tilt the lens so the hinge line is at your feet and then the plane of focus will be parallel to the ground. However, this means you're losing out on the dof behind the plane of focus. It's better to have the plane of focus angled up in order that the far limit of the dof behind the plane of focus is just in the ground (I guess whatever this distance is could be called the 'hyperfocal' distance). For instance, using a 35mm lens on a DB with a CoC of 0.003mm, with the lens 120cm off the ground and shooting @f11, focussing at about 3m and adding a forward tilt of 1.7 degrees will put the hinge line at your feet and the far limit of the dof just into the ground, with the near limit at about 40 degrees to the horizontal. The actual plane of focus will be at about 22 degrees to the horizontal. It all sounds a bit hellish, but in practice focus at about 3m and tilt the lens 1.5 degrees and you should be good. Focus too far and the plane of focus will be shallower (further edge of the dof deeper in the ground); focus too close and the plane of focus will be steeper (further edge of the dof above the ground). So, if in doubt, focus a little bit too far away.

    Tilts/swings done on the fly (i.e. with no chart of presets to hand) really need to be observed, so you need to shoot tethered or use a ground glass to see exactly what's going on, especially in systems where you're going to possibly need to refocus as well, since you're effecting a base tilt (e.g. long lenses on pancake cameras). Given the size of todays average ground glass, this takes a good loupe. The new Linhof and Studio / Silvestri one, 12x with a square base (for getting into the corners) is perfect. If you use an IQ back then you also have live view as an option, or you could use the shoot-check-adjust-shoot-check-adjust routine. I find a ground glass infinitely more satisfying than the shoot-check-adjust routine.

    In terms of setting fractions of a degree, I found the Techno to be easier than the RM3d/i, simply because the gearing is finer. The current set of Alpa T/S adapters allow the finest setting of T/S, but unfortunately are limited to only certain lenses.

    Disclaimer: Throughout all this, I have assumed the sensor plane is vertical and the ground plane is perpendicular to it.
    The gear ratio of the techno is not finer than the RM3di. This is explained above...
    US Representative, Arca-Swiss International
    R-Line Technical Cameras, Large Format View Cameras, Tripod Heads D4, D4m, P1, P0, Z1, Z2, C1 Cube.
    http://www.rodklukas.com/arca-swiss 480-755-3364
    Instagram @arcaswissusa Facebook @arcaswissusa

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    Re: Arca Rm3di

    I've had my Rm3di for as long as Jack has, since August of 2011. I had F-Metric Compact 6x9 before that and used both camera with P45 DB.

    The focusing is the main challenge with both View and Technical camera whether one is using Tilt or Swing or not. Tilt and/or Swing just makes the challenge bigger, at least by a magnitude of 10. None of currently available methods of focusing; GG, LV, tethered shoot and using a laser range finder, are a perfect solution.

    I am only going to talk about 'focusing' here, not 'composing' or 'Tilt.'

    For me at least, GG is not an option. I tried too many different types of GG and loupes with my F-Metric and gave up on the idea of using GG with MFDB. Personally, I only have a limited experiences with the LV with MFDB, and I hope that we may have the 'perfect' solution soon. A tethered shoot provides the best possible focus but by means of trials and errors.

    The reason why I picked Rm3di is based on the possibility of achieving the perfect focus every time utilizing its very precise 'helical' focus ring and precise measurement of object distances. It is my assumption that Arca-Swiss originally designed its Rm3di with the same design criteria. Arca-Swiss is finally making available 'E-module', which I am only familiar with by reading about it, to measure 'precise' distance.

    Both ALPA and Arca-Swiss are providing means of 'precise' focus; HPF rings from ALPA and a built-in Helical focus from Arca-Swiss, with different twists. There are two significant differences between two methods; rotational pitch and indexing method. Many are focusing on either advantage or dis-advantage of the larger rotational pitch of helical focus ring of Arca-Swiss over the HPF ring of ALPA.

    I will use the example of using SK35XL on both mounting methods.



    As can be seen, Arca-Swiss helical ring needs to rotate approximately 4 times as much as HPF ring. You make your own conclusion if it is good for your workflow or not.

    Another difference is the method of marking distance scale. HPF ring is marked with the actual object distance for a particular lens while A-S Helical ring is just simple index (0 to 34.4 for each revolution, up to 5 revolutions if necessary).

    Each has both pros and cons; HPF ring eliminate one step of 'look up table' that A-S uses; measure the distance with a laser range finder then dial in the distance while you have to look up a table which converts the measured distance to a focus setting for Arca-Swiss. On the other hand, HPF ring only shows 9 discrete distance marking between 2.5 m and infinity while the look up table from Arca-Swiss shows 34 discrete focus settings for the same distance range. HPF ring has tick mark for each angular degree but has the actual distance marking at every 5 degrees (except first 5 degrees from infinity). For example, it show the distance setting of 9.64 m at 5 degree and 4.86 m setting at 10 degree, therefore, you have to make a quick interpolation if your distance measurement is 7.5 m to find the correct focus setting. Done? The answer is 6.5 degree. ALPA makes it available a print out of HPF ring setting for each degree in PDF format for each lens, and they are 7 pages per lens.

    The real advantage of the simple indexing used by Arca-Swiss is when one takes advantage of an iPhone and some mathematic. It is possible to develop a 'lens equation' which converts the object distance into the required angular rotation for an individual lens, and run it on an iPhone. That's what I had in mind when I chose Rm3di and I've been using it from the beginning. Measure the distance with a laser finder, then tap in the number into an iPhone and it will show the exact focus setting; i.e., White 7.3

    The development of 'lens equation' requires the combination of 'optical lens equation' and 'curve fitting' by numerical analysis. A simple 'optical lens equation' does not work in entire object distance range since the modern lenses for MF are very complex with multiple lens elements. It is necessary to measure the actual focus settings for different distances or just use the data provided by Arca-Swiss. I did my own measurement.

    Can this method be used with HPF ring? It can be done if the distance markings are replaced with a simple angular degree indexing of 0 - 270, by pasting a simple adhesive tape over distance marking. It is not easy to find 37.5 degree from the scale marked with 9.64, 4.86,3.27, etc.

    For me, Rm3di provides the best solution to make perfectly accurate focus under the presently available technologies; Leica Disto D5 and a home brewed program on an iPhone.

    I will discuss the subject of Tilt or Swing on a separate post.

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    Re: Arca Rm3di

    Very interesting description of rm3di use, thanks! I have come to realise that focusing is a very personal issue, each have their own ways. I actually find it easier to succeed when tilt/swing is involved. It may be hard to succeed to cover all objects with the wedge, but actually placing it is often easier than focusing flat.

    We often think of tilt in the standard upright grand scene situation, but if you have a shooting style when you use longer focal lengths to make small cutouts of semiabstract parts of the ground or similar you often have the whole camera tilted and need to tilt the focus plane too, these scenarios cannot be solved with a table, but gg must be used. Same for (semi) closeup work. The Techno with its gg is a bit more difficult to use but is more open-ended concerning shooting style.

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    Re: Arca Rm3di

    Quote Originally Posted by Jae_Moon View Post

    The real advantage of the simple indexing used by Arca-Swiss is when one takes advantage of an iPhone and some mathematic. It is possible to develop a 'lens equation' which converts the object distance into the required angular rotation for an individual lens, and run it on an iPhone. That's what I had in mind when I chose Rm3di and I've been using it from the beginning. Measure the distance with a laser finder, then tap in the number into an iPhone and it will show the exact focus setting; i.e., White 7.3

    The development of 'lens equation' requires the combination of 'optical lens equation' and 'curve fitting' by numerical analysis. A simple 'optical lens equation' does not work in entire object distance range since the modern lenses for MF are very complex with multiple lens elements. It is necessary to measure the actual focus settings for different distances or just use the data provided by Arca-Swiss. I did my own measurement.
    +1

    With the eModule, the number of data points and the specific lens behaviour built into the numbers takes the precision to a new level. I am still learning to use mine, but focussing on close objects is just so much easier, and I can do with a much higher level of confidence.

  34. #34
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    Re: Arca Rm3di

    Quote Originally Posted by RodK
    The gear ratio of the techno is not finer than the RM3di. This is explained above
    For the tilt mechanism? Really? From memory, it certainly didn't feel that it was, and given the limited movement of the thumb wheel on the RM3D/i I would be surprised. I felt it was possible to set tilt more precisely with the Techno. A/S should replace the white dot with a small horizontal line or an arrow, and add some divisions between degree markers IMO. Also, tilting on the RM3D/i whilst closely observing the ground glass wasn't exactly easy either (since the control is on the bottom, front, left of the camera) - on the Techno the control is more 'naturally' positioned and easier to operate, since you can grip the whole knob easily - even with gloves on (Full disclosure: I am right-handed).

    Quote Originally Posted by RodK
    That is why most stay below 7x for a magnifier.
    Try the new 12x loupe from Silvestri - it's a gem for nailing focus, and with its square base you can get right to the corner of the ground glass. The issue of magnifying grain is generally overstated - you can use quite a high powered loupe and still observe changes in the plane of focus.

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    Re: Arca Rm3di

    While i enjoy using the rotaslide for composition with my Rm3d, i'm really pleased not to have to use a loupe all day long... the index' system rocks !

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    Re: Arca Rm3di

    Quote Originally Posted by RodK View Post
    I am sure you know what you are doing, but a 20x loupe creates more focus problems than it solves as it magnifies the glass pattern so much it can interfere with the image you are trying to focus.
    With standard to longs it may be OK, but with wides I believe it becomes a liability. But if you feel it works for you, then stick with it.
    That is why most stay below 7x for a magnifier.
    Rod
    I do know what I'm doing . You can read about my focusing tests at:
    Review: Linhof Techno in the appendix section. I don't just *feel* that it works, I've made a controlled repeatable test and shown that it works. I haven't tried Arca-Swiss's ground glass though, some say it's not as good as Linhof's

    Quite simple: 7x loupe = relatively high risk to miss focus, 20x loupe = very low risk to miss focus. There are people that are more skilled than me though and can do with the 7x nicely, or have a more relaxed view than me on focusing precision. However, a user that feels that focusing is not confident on a view camera really should try using a high magnification loupe. Saying that it won't help or even makes focusing worse without actually testing it is not fair.

    Most stay with a 7x loupe because of this grain myth that noone cared to put to the test. I can understand back in the 8x10" and 4x5" days that people did not want to use more than 7x, you really did not need more and then it's nicer to have a wide field of view and grain-free image. I'm surprised that the same large format film recommendation is repeated for digital where the format is much smaller. Of course you need more magnification.

    Actually, if optics made it possible an ideal magnification would probably be around 40x, but it is difficult to make such a loupe, you would then need to design it as a pen microscope, and the tiny field of view could be a problem.

    And yes you do see grain, but the effect is similar to the difference of watching a picture on a tiny screen like on an iphone, and then watch the same image on a larger screen, with the same resolution, you still get a better understanding of the image.

    The goal is not to see a pretty picture, the goal is to see when the focus peaks (=contrast peaks), and it's considerably easier to do that when you *without effort* see a larger image with grain and all, also with wide angles. Wide angles does not make it different, oh well one thing is different, the high magnification loupes cannot be tilted so I do have a 10x tiltable loupe to for looking into corners of wides.

    If you do not believe me I can only recommend to repeat the test described in my Linhof Techno review, where I clearly focused with higher precision when using the 20x loupe rather than the Silvestri 10x (which is more like a 6x though).

    The attached image shows a realistic simulation of what you see through the 20x loupe, based on a true macro photography of the Linhof Techno standard ground glass. Yes the image is a bit grainy, but contrast differences when turning the focusing knob is much easier to see than with a smaller magnification. (The image is showing a detail of a Swedish bill which is quite low contrast print in itself.)

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    Re: Arca Rm3di

    By the way, here's an example of a shooting style that fits a view camera very well, represented by the excellent British landscape photographer David Ward:

    Into The Light | Gallery

    Actually he uses 4x5" Technikardan as he loves Velvia 50 (which was to be discontinued, but is now back, woohoo!), but digital it could be a Techno. Why I mean this style is well-suited to view camera is that you have many images with no visible horizon, camera pointing down and flat(ish) subjects that require tilt. Shooting that style with a RM3Di would be a waste, as you would have to use the ground glass anyway.

    I've attached one of my own images too. It was shot with a 120mm lens, 10mm fall, the camera pointed downwards, and ~2 degrees of tilt. How would you shoot that with an RM3Di? Using the ground glass I suppose.

    Not saying that everyone should point their camera towards the ground and shoot pebbles, leaves, rocks and minimalist patterns, but as you do get to pay a lot for the helical focusing mounts you should think about what you want too shoot and how often you end up using the ground glass anyway.

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    Re: Arca Rm3di

    once i found a very interesting article on luminous landscape about focus a tilt lens for 35mm cameras: Focusing Tilt Shift Lenses

    the author - david summerhayes - provided a formular to calculate the angle of tilt needed depending on the hight of the optical axis above the decided plane of focus. (sensor plane perpendicular to it).

    just use the arcsine of your lens' focal length divided by the distance from the object plane to the axis of the lens.

    measure the hight of the middle of your lens above ground and calculate (or read a selfmade table based on the formular) your tilt angle to get the ground in focus.
    if you are using a standard setup with the sensor plane leveled, not pointed downwards no problem.
    but theoretically it should be no problem to use this method when pointing the whole camera downwards too - just measure the distance to the ground not vertical but in the same angle in which the sensor plane is tilted to the ground. should be the same affect as if you were a little higher with vertical sensor (meaning slightly less tilt angle), or am i totally wrong?

    i tried it once and it worked very well.
    in his description he first gets the right angle and then focuses anywhere in the scene where he can find good contrast.
    that's a little advantage to groundglass users ;-)
    www.thomasebruster.com
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    Arca Rm3di|RS90|SK43|RS28|CFV-50

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    Re: Arca Rm3di

    An easy formula to calculate the tit required to put the hinge line at your feet:

    t = 90 - arctan h/f

    where t = tilt; h = height of the lens and f = focal length at infinity. Assumes this distance (f) is the same as the focal length i.e. not applicable for some lens designs. Also assumes camera back isn't tilted.

    e.g. a 120mm (=12cm) lens which is 120cm off the ground. Then h = 120, f = 12:

    t = 90 - arctan 120/12 = 90 - arctan 10 = 5.7 degrees

    ...or you can just use the ground glass

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    Re: Arca Rm3di

    Quote Originally Posted by Jae_Moon View Post

    For me, Rm3di provides the best solution to make perfectly accurate focus under the presently available technologies; Leica Disto D5 and a home brewed program on an iPhone.
    would you mind to provide your little home brewed program?
    unfortunately i'm not able to program one ...
    www.thomasebruster.com
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    Re: Arca Rm3di

    I discussed the challenge of making perfectly accurate focus using tech cameras with MFDB in previous post (#31).

    A quick summary, at least in my case, the best possible method with the presently available technologies to achieve perfect focus is by using 'lens equation' with accurate object distance measurement and a precisely indexed focus ring. A lens equation, for a specific lens with a specific focusing system, can be developed mathematically. The 'lens equation' will provide the required angular rotation of a focus ring for a measured object distance.

    First, I would like to 'rant' against all View Camera and Tech Camera manufacturers for their failure to promote (i.e. to educate their customers) properly how to use the features they are building into their camera. It is a shame that they let the customers to rely upon HF (hyper focal) or 'focus stacking' for proper focusing, or '35mm rule of thumb' for lens tilt calculation after spending a small fortune on equipment that boast 'multi mega pixels', '13 f-stop dynamic range' and 'lens with resolving power to see the sub atomic particles', etc. Why can they develop and provide more than a 'satisfactory' solutions to the challenges their customers face? Enough with ranting.

    Let't talk about Tilt or Swing in Tech Camera application.



    A simple geometric diagram for Tilt (both camera and lens) is shown above.

    The Plane of Sharp Focus is defined by two points photographer select to be in 'sharp' focus, Near Subject (or Object) and Far Subject. Camera Height, Camera Tilt angle and a specific lens are also defined by photographer to compose the image properly. The lens Tilt Angle and the required Focus Distance are the results of these five input data (the location of Near and Far Subjects, Camera Height reference to the ground, a lens focal length and Camera Tilt Angle). In addition, Near and Far Wedges of Acceptable Sharpness (Angular DOF) are defined by a user selected CoC.

    The real challenge of using Tilt or Swing with View Camera or Tech Camera is not finding a lens Tilt Angle but the required Focus Distance after a tilt is made. Harold Merklinger published two books (The Ins and OUTs of Focus, Focusing the View Camera) on the subject of Lens Tilt in details.

    Once I was satisfied with the results of 'Lens Equation' in achieving a perfect focus with a measured Object Distance, I decided to tackle the challenge of Lens Tilt (or Swing). It is rather complex geometric calculations but doable using a spreadsheet, such as Excel or Numbers. It took me much longer than I expected (my mathematical brain atrophied significantly over last 40 years) but I completed the project and have been using since last Spring.


    The picture above shows the setup I use for both leveled and lens tilted application. It maintains the exact geometric configuration between Rm3di and Disto 5 so I can always accurately measure the Object Distance or Near (Far) Object locations. Since all Disto measurement are offset from Lens Axis, Lens Nodal Point and DB sensor plane, proper corrections are made in the program.

    Near (and Far) Object locations should be measured by their horizontal and vertical distance from the lens nodal point. Disto 5 has a function to measure them (Direct Horizontal Distance).

    I made a quick shot this morning after reading "Torger's" comment. I used SK90, placed two $20 bills on the floor (1.96m and 3.22m away from the camera, and the nose of Andrew Jackson was the targets), camera was tilted 23.8 degree and the camera height was 0.96m. The required lens tilt was 4.82 degree and the calculated focal distance was 2.14m, therefore the index setting of Red 22.1. The aperture setting was 8.0.


    Images are directly from C1 without any enhancement.

    100% of Front US$20 bill.

    100% of Back US$20 bill.

    One additional picture I took while working on the program, Lens Swing. I superimposed 100% images of two blocks, front and back.






    This is the one man's story to use a tech camera, Rm3di, for its full potential.

    There are several mechanical designs of Rm3di which I wish they improve soon.

    1. There are no indentations (mechanical click) for both vertical and horizontal shift center positions.
    2. Thumb dial for Lens Tilt needs major improvement, for both accuracy of setting and ease of use.
    3. Helical ring is too tight to rotate. I understand its need to stay at a set point but the friction could be much less.
    4. Focus setting point should be a 'fine line' much closer to the index markers.


    Jae Moon
    Last edited by Jae_Moon; 29th March 2013 at 08:31.
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    Re: Arca Rm3di

    Quote Originally Posted by Jae_Moon View Post
    ...
    Impressive work. As the RM3Di allows for precise setting of a lens distance and a tilt angle, laser measurements with a special app that has the mathematics can indeed solve the problem which you prove. Nice. If I had an RM3Di I would certainly like to have such an app.

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    Re: Arca Rm3di

    what sort of tilt angle tolerance can one expect to set/hold and measure?

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    Re: Arca Rm3di

    Quote Originally Posted by jlm View Post
    what sort of tilt angle tolerance can one expect to set/hold and measure?
    I am assuming that your question was for Rm3di. It has +/- 5 degree with markings for each degree. I can only reliably set at 0.5 degree accuracy, at the best. It's 'thumb wheel' design is a sub-standard one. I think Cambo's (also ALPA's) thumb screw design is easier to use. Since one can calculate the tilt angle very accurately and the magnitude of tilt angle increases with longer focal length lenses, all manufacturers should consider using a 'caliper' based tilt adjustment which allows 0.1 degree accuracy. So far, they haven't been hearing demands for improvement.

    Jae M

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    Re: Arca Rm3di

    Quote Originally Posted by torger View Post
    Impressive work...
    Indeed. However, I get the feeling that this is heading in the direction of a solution looking for a problem. I don't remember seeing any pictures of Ansel Adams, Paul Strand or Edward Weston with an abacus. With experience, this is all easily achieved 'in practice' using those two things either side of your nose and the 'app' running in the space between your ears
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    Re: Arca Rm3di

    Quote Originally Posted by f8orbust View Post
    Indeed. However, I get the feeling that this is heading in the direction of a solution looking for a problem. I don't remember seeing any pictures of Ansel Adams, Paul Strand or Edward Weston with an abacus. With experience, this is all easily achieved 'in practice' using those two things either side of your nose and the 'app' running in the space between your ears
    Yes indeed, if I was using an 8x10 or even 4x5 with 'BRIGHT' GG which allows me to see the image, I wouldn't have bothered. With MFDB, we are flying blind. If one cannot see clearly while flying an airplane, avionics come very handy. No shame in relying on 'grey matter' between ears.

    Jae M
    Last edited by Jae_Moon; 29th March 2013 at 11:48.
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    Re: Arca Rm3di

    I don't think Arca-Swiss has taken tilt that seriously, and most RM3Di users don't either. In architecture, which I would say is the main application for RM3Di, tilt is not used that often at all. In landscape I see that tilt has lost popularity since the 4x5" view camera days, and actually also shift. Focus stacking is a new technique which seems to be increasing in popularity.

    One reason for this I think is that shooting styles indeed have changed, more wide angle less of longer focal lengths, but also that cameras have changed, and that there's an almost unhealthy obsession with resolution. I think the DSLR competition has made many even more obsessed with resolution as it's the easiest spotted and most obvious advantage.

    There are indeed new type of compositions you can do with focus stacking, but often I see stacking used in scenarios when you could focus conventionally, but someone has this fancy Rodenstock lens and IQ180 and wants to shoot at f/5.6 to minimize diffraction. My take is that if you drop below f/11 the depth of field becomes for 90% of the scenes unpractically short, so I will not get gear that gives me an urge to shoot at larger apertures than that . There's nothing wrong with f/11 even on IQ180, but price must come down before I can shoot f/11 and not get the feeling I'm wasting money .

    My normal working range is f/11 for 80% of the images, f/16 for 15% and f/22-32 for 5% of the images. If I had to drop down a stop or two it would be much harder to make images the way I want them to look (i e "in focus" all over).

    Then we have the 645-fullframe with 90mm or even 70mm image circles, shifting margins are a bit smaller than before(?) or at least it's easier to detect sharpness falloff, and that has caused many to reduce the use of shifting.

    The pancake cameras are more limited in movements, many don't even have tilt or have very expensive tilt mounts to select lenses, which further have contributed to making a shooting style with less movements popular.

    RM3Di ultra-precise focusing precision is a natural part of this development, but I think it has now gone into overkill mode. Creative possibilities are crippled in the search for even more resolution and precision which is now at a level that don't contribute to anything valuable. It's more than a help to "focus in the blind", the precision is more than any 8x10" user could dream about. I think this "need of precision" is not coming from an actual need in creative imagemaking, but rather from an unhealthy race in resolution.

    I have a Canon system too. My TS-E 24mm II has actually more flexible movements than an RM3Di - I can tilt in any direction and the compared to an IQ180/Rodie40 I have larger useful shift range too. To me a MF technical camera should not only be a carrier of higher image quality, it should also carry better creative possibilities in terms of movements. Resolution is becoming a less important differentiator for each year.

    Then we have the usability of ground glass on digital. I don't agree that we are flying blind. It is a challenge though, and require some practice and skill, I admit that. As far as I can see it was not really easier on a 4x5" though. The corners on a 90mm on a 4x5" frame was as dark as a 35mm on digital, the incoming light angles are the same so how can it be different? Actually with Rodenstock you have f/4 and retrofocus (brighter corners) so that must surely be easier than it was on 4x5", and I'm sure Linhof's new bright ground glass is brighter than most used on their large format cameras. Sure, the format is smaller so you need more magnification on the loupe. That's the difference. Due to some grain-myth many stay with the same magnifications they had on 4x5" and then of course it becomes more difficult.
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    Re: Arca Rm3di

    Quote Originally Posted by torger View Post
    ...
    RM3Di ultra-precise focusing precision is a natural part of this development, but I think it has now gone into overkill mode. Creative possibilities are crippled in the search for even more resolution and precision which is now at a level that don't contribute to anything valuable. It's more than a help to "focus in the blind", the precision is more than any 8x10" user could dream about. I think this "need of precision" is not coming from an actual need in creative imagemaking, but rather from an unhealthy race in resolution.
    ...
    Oh well... don't you think pancake camera users, as buyers of quite expensive gear, have done their homework and selected the equipment that suits their needs best too ?
    It's like saying your Techno hampers creativity because it has to be shot on a tripod. Isn't that crippling your creative possibilities ? It isn't if it's not the way you shoot, right ?

    My back lacking LV, focus masks or a usable 100% view, I certainly consider the focusing precision to be very valuable and not overkill at all.
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    Re: Arca Rm3di

    One of the facts that drops out of the maths for tilt shift lenses is that the focus along the line of the lens axis remains just the same as whether the lens is tilted or not.

    i.e. if you looks straight through the middle of the lens (rear tilt helps) you can use hyperfocal focusing, tilt will only change where the near and far DoF bounds converge to.

    Things get more complicated with front tilt but they can be worked out.

    If you want to see tilt in practice, have a look here.

    http://static.timparkin.co.uk/static/focus/index2.html

    If anybody would like a medium format version just let me know what CoC and lens range to use and I'll tweak the figures..

    The maths assumptions to make things simple start to break down near 7 degrees of tilt. You get the idea hopefully though.

    Tim

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    Re: Arca Rm3di

    This is wonderful! How hard is it to do a MF version? Something say with COC of .007 (?) and a 55 and 90 mm lens?

    Is this assuming lens tilt is on axis with the center of the lens?

    Thanks much -

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