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Thread: A Comparison of Technical Cameras

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    A Comparison of Technical Cameras

    This year, we decided to invest in a portable technical camera, if it was possible to meet most of our shooting situations. So, for the last six months we evaluated the various smaller technical cameras currently available on the market. Our analysis, or at least our approach, might benefit other photographers who are considering the same investment.

    First, we list the major features of importance to us that we deem essential requirements to making such an investment:

    1. Front lens tilt+swing with any lens (and retaining infinity focus)
    2. Rear x-y shift of MFDB suitable for stitching
    3. Sliding back optional
    4. Compact and lightweight enough for easy portability, setup and breakdown
    5. Schneider and Rodenstock digital LF lens choices from 23mm - 210mm
    6. Untethered focus accuracy (other than infinity)
    7. Hand holdable w/ accurate focus (other than infinity)
    8. Zoomable EVF w/ shift indicator for all supported lenses
    9. Compact tilt-able 6x9 magnified (4X-6X) reflex GG finder w/ adjustable diopter

    Then, we create a table to indicate which technical cameras either meet or fall short of our desired requirements (see our attached table below).

    Our conclusion: Only the Arca-Swiss RM3D came closest to our desired features. Most, if not all of the other technical camera choices could not give us reliable untethered performance and handling as with the RM3D. The only shortcoming that we found with the RM3D is the lack of simultaneous swing, or preferably the multi-directional tilt-swing ability as found in cameras like the Sinar arTec and the Cambo WRS. However, our lens movement needs are predominantly a small amount of tilt, so we are happy with this trade-off in favor of the better untethered performance.
    Last edited by David Klepacki; 30th June 2013 at 21:29.

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    Re: A Comparison of Technical Cameras

    David, the artec ( which I dont own) has:

    1. An inbuilt sliding back - which is a missing tick on your table,
    2. a 3x magnifier with inbuilt bellows to shade from sun (another tick)
    3. rear y movements and front X movements ( so I gues only a half tick ) - but controls on photographers side of camera

    It also has front tilt AND swivel capability ( but you have no interest in swivel apparently ) so no ticks there

    As for lenses - the Sinar uses Sinar mounted rodenstock sourced lenses

    and finally - Sinars focussing accuracy via ground glass for ANY focal length - is just fine - so add another tick.

    I agree you cant hand hold an artec - but thenm again I wouldnt try and hand hold the arca either ! -

    Since I have no prejudice or bias or buyers remorse - I am purely interested in the value proposition that this gear delivers on a cost / benfit basis.

    One thing I can say - it looks like ( for now) the arca has a definite advantage over the Sinar atec as far as cost goes !!

    PS I would another radvantage that arca has over Sinar - and that is teh ability to use mutliple backs on same camera by buying an adaptor?

    Pete

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    Re: A Comparison of Technical Cameras

    re Cambo WRS:
    There is a mono reflex viewer for the WRS.
    It was designed for the Ultima Sliding Back but it fits on the WRS:
    http://www.cambo.com/Html/products_p...t/Item886.html

    Strictly speaking not all the lenses for the WRS are available in T/S mount.
    Shortest focal lenght, AFAIK, is 28mm... but only the Rodenstock can be mounted in a T/S lens panel. The shortest Schneider that can be mounted in a T/S panel is the 43XL.
    On the other hand it's fair to say that you can get T/S for (almost) any focal lengths on the WRS.

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    Re: A Comparison of Technical Cameras

    Actually a nice list to get a brief overview!

    Just thought to add some thoughts about the uniqueness of the respective cameras (which may tell something about the underlying idea of the cameras) … please feel free to correct me if I am wrong…

    BiCam:
    smallest, lightest tech camera with movements (limited, though)

    Horseman:
    lightest tech camera with 4-way shift on the rear (not geared)

    WRS:
    smallest + lightest tech camera that provides geared, full movements (4-way-shift on the rear & T/S on the lens)
    (sole tech camera that provides a dedicated level head)

    arTec:
    sole camera with integrated sliding back (i.e. the rear standard of the actual camera is designed as sliding back).

    Alpa Max:
    camera interface can be shimmed (Alpa also seems to provide the most extensive set of accessories)

    Techno:
    most compact view camera (AFAIK)

    Rm3D:
    unique focussing mechanism

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by PeterA View Post
    David, the artec ( which I dont own) has:

    1. An inbuilt sliding back - which is a missing tick on your table,
    2. a 3x magnifier with inbuilt bellows to shade from sun (another tick)
    3. rear y movements and front X movements ( so I gues only a half tick ) - but controls on photographers side of camera

    It also has front tilt AND swivel capability ( but you have no interest in swivel apparently ) so no ticks there

    As for lenses - the Sinar uses Sinar mounted rodenstock sourced lenses

    and finally - Sinars focussing accuracy via ground glass for ANY focal length - is just fine - so add another tick.
    Pete,

    1. My point is that the arTec sliding back is NOT optional (i.e., it cannot be removed from the camera). So, no tick in our table.
    2. The arTec viewer is not a reflex magnifier nor does it give a 6x9 view on the GG. So, no tick.
    3. Rear x-movement is critical for horizontal stitching capability. So, no tick.

    I do acknowledge the use of Rodenstock lenses on the arTec, but it is important for people to know that the Schneider apo digitars are not available for it.

    Focusing accuracy is NOT as fine as you think on GG for any focal length (for any of the technical cameras). Have you actually measured this for yourself? Attached below is an example of the accuracy of the RM3D, shot untethered and without using ground glass focusing. It was taken with a Rodenstock Digaron-S 100mm lens wide open at F4 at a distance of 4.21 feet as measured with a laser meter.

    No other technical camera can produce this kind of accuracy without being tethered.
    Last edited by David Klepacki; 30th June 2013 at 21:29.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by thomas View Post
    Actually a nice list to get a brief overview!
    Thank you. Actually, we have pages of notes on each of the cameras, and I only provide the summary table to show the net balance among all the cameras. You have summarized nicely the other advantages.

    One more thing I should add about the RM3D is that shimming is not necessary as for the other technical cameras. Arca-Swiss made it so that the registration distance to any lens is much shorter than could ever be needed. So, once you calibrate the RM3D to your back using its built-in helicoid mechanism, it is equivalent to the shimming process of Alpa.

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    Re: A Comparison of Technical Cameras

    After a lot of research, i've found that the only camera that fits the bill was the Arca RM3D... so i've bought it !

    it have all of it.. the only thing missing is an adjustable adapter for MFDB... but now the kapture group can do it !

    Alpa coming with new focusing ring + the KG sliding back... it becomes more interesting !
    But don't forget that with Arca you can also use your existing RM3D lenses with an M line Two... it requires just a simple adapter plate !
    For me, that's a big plus !

    1. Front lens tilt+swing with any lens (and retaining infinity focus)
    2. Rear x-y shift of MFDB suitable for stitching
    3. Sliding back optional
    4. Compact and lightweight enough for easy portability, setup and breakdown
    5. Schneider and Rodenstock digital LF lens choices from 23mm - 210mm
    6. Untethered focus accuracy (other than infinity)
    7. Hand holdable w/ accurate focus (other than infinity)
    8. Zoomable EVF w/ shift indicator for all supported lenses
    9. Compact tilt-able 6x9 magnified (4X-6X) reflex GG finder w/ adjustable diopter

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by David Klepacki View Post
    One more thing I should add about the RM3D is that shimming is not necessary as for the other technical cameras.
    actually shimming the camera interface is not necessary with any of those cameras (with helical focus mount) as you can easily adjust the lens for infintiy. However the shimming set is a unique offer of Alpa.

    Musing about the Techno... if such a camera would just provide additional rails - exchangeable for every lens and with a high resolution distance indication on it - it would be easy to gain the same (or similar) level of accuracy as on the Rm3D. If they would equipp any of those additional rails with a lock for infintiy it would be even usable for architecture or landscape (or any field where you need accurate infinity focus).
    well ...
    Last edited by thomas; 10th September 2010 at 08:41.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by thomas View Post
    actually shimming the camera interface is not necessary with any of those cameras (with helical focus mount) as you can easily adjust the lens for infintiy. However the shimming set is a unique offer of Alpa.
    Thomas

    Not quite true . You can set any lens with a helical mount to infinity and then you believe it is set to infinity . But the flange focal length might be wrong by just 0.02 or 0.05 mm .
    I have seen the ALPA technician going thru the shimming procedure for my digital back adapter and I must say , it is very well visible if the flange focal length is incorrect and it is mandatory to have correct adjustment to
    obtain the best results (for infinity ?)

    The ALPA is the only camera offering this adjustment .

    Also , we should not forget , there will never be an "all-in-one" camera suitable for all purposes and having only the goodies we all love so much .

    BTW , I am very much looking forward to see (and get) the announced addtional precision focusing device for the ALPA lenses .
    Regards . Jürgen .
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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by jotloob View Post
    Not quite true . You can set any lens with a helical mount to infinity and then you believe it is set to infinity . But the flange focal length might be wrong by just 0.02 or 0.05 mm .
    I have seen the ALPA technician going thru the shimming procedure for my digital back adapter and I must say , it is very well visible if the flange focal length is incorrect and it is mandatory to have correct adjustment to
    obtain the best results (for infinity ?)
    all true. But you can adjust the focus lock position on the lens - which is in effect the same as shimming the back.
    See here: http://forum.getdpi.com/forum/showpo...postcount=4572

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    Re: A Comparison of Technical Cameras

    Why should you change a perfectly calibrated focus ring when the tolerances are occuring in the position of the sensor? The advantage of the Alpa is the exchangeability of components between different cameras. Once you have a back with a calibrated mount everything else fits and can be changed.

    There are some „experts“ that claim that this kind of calibration is only valid for infinity. This is only half true. If the reference plane for precise flange measurement is the groundglass (which is the case on Alpa's) and the correction is done on the back/adapter to fit there, untethered close range imaging gets more precise too, because the back is now in the exact same position as the groundglass. Looks like an argument to cope more reliably with the shallower DOF.
    When you correct on the helical focus, you might get precise infinity with the back, but you move the tolerance to the groundglass. Doesn't sound too promising for me, and is the case for every camera where sensor tolerance correction is done that way.


    In my opinion regarding Alpa lens availability and untethered focus precision this chart is not correct.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by jotloob View Post
    Also , we should not forget , there will never be an "all-in-one" camera suitable for all purposes and having only the goodies we all love so much .

    BTW , I am very much looking forward to see (and get) the announced addtional precision focusing device for the ALPA lenses .
    The Alpa is indeed a very nice camera, but it lacks many of the features that we really wanted, especially tilt ability with wide to normal lenses and the option of having high focusing accuracy without being tethered and without swapping out ground glass. Even the newly announced "precision focusing mechanism" for the Alpa lenses will not resolve these issues.

    For us, the Arca-Swiss RM3D comes very close to an "all-in-one" camera for our purposes.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by smei_ch View Post
    In my opinion regarding Alpa lens availability and untethered focus precision this chart is not correct.
    Alpa does not offer all Rodenstock lenses. For example, you cannot obtain the Rodenstock APO-Sironar Digital 135mm lens for any Alpa camera.

    As for untethered focus precision, the above image that I posted is smoking gun proof. I challenge anyone to repeatedly and consistently obtain such precision without being tethered and without using ground glass focusing on an Alpa or any other technical camera. Maybe you can achieve similar results with a tremendous amount of focus bracketing, but even then it is highly unlikely.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by smei_ch View Post
    Why should you change a perfectly calibrated focus ring when the tolerances are occuring in the position of the sensor? The advantage of the Alpa is the exchangeability of components between different cameras. Once you have a back with a calibrated mount everything else fits and can be changed.
    true

    When you correct on the helical focus, you might get precise infinity with the back, but you move the tolerance to the groundglass.
    also true.
    In my case obviously GG and sensor match. Actually two sensors match...
    If not, you would have to adjust the GG, too (well, for instance with shims).

    Still, I agree that Alpa's interface shimming is in this regrad the most mature solution, no doubt.
    Except for Arca's approach... which is different, but as accurate.

    In my opinion regarding Alpa lens availability and untethered focus precision this chart is not correct.
    you will never ever match focus precisely at, let's say, 20 meters with the 40HR focussing on a GG - not even on Alpa's GG. The magnification is simply too low.
    With the Rm3D you can nail 21,35 meters spot on... without the need of any GG (that you actually rather use for composition on the Rm3D).
    I think this is what David is referring to here.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by thomas View Post
    true

    .....

    you will never ever match focus precisely at, let's say, 20 meters with the 40HR focussing on a GG - not even on Alpa's GG. The magnification is simply too low.
    With the Rm3D you can nail 21,35 meters spot on... without the need of any GG (that you actually rather use for composition on the Rm3D).
    I think this is what David is referring to here.
    Not the very best example. Even full open with f4 and a very aggressive CoC of 0.032 (equals enlargement to 90*120cm) DOF reaches from approx. 7.8m to infinity. This is an area where focus accuracy is almost irrelevant. Close range is where these things really matter.
    Just my 5 cents.....

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by smei_ch View Post
    Not the very best example. Even full open with f4 and a very aggressive CoC of 0.032 (equals enlargement to 90*120cm) DOF reaches from approx. 7.8m to infinity. This is an area where focus accuracy is almost irrelevant. Close range is where these things really matter.
    Just my 5 cents.....
    oh, the numbers :-)
    they don't matter a lot as you won't find anything of it reflected in the actual image.
    Don't know the 40HR, though, but with the 47XL 20meters are not really sharp when you set the lens to infinity at f8... though the numbers tell something different. Good sharpness starts at around 28 meters meters with the 47XL.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by thomas View Post
    oh, the numbers :-)
    they don't matter a lot as you won't find anything of it reflected in the actual image.
    Don't know the 40HR, though, but with the 47XL 20meters are not really sharp when you set the lens to infinity at f8... though the numbers tell something different. Good sharpness starts at around 28 meters meters with the 47XL.
    My calculated DOF was for a lens set to 21m, not infinity. And if you focus to 25 or 18m doesn't change this much. There absolute accuracy on your focus ring is not really important.
    This is different for close distances, where the scales on helicals spread already and a more precise indication will come in handy.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by smei_ch View Post
    My calculated DOF was for a lens set to 21m, not infinity. And if you focus to 25 or 18m doesn't change this much.
    well, but your calulated DOF will not reflect the reality on a high res sensor.
    I canceled DOF calculations at all. I do see a difference when I set the 47XL to 18m or 25m... apart from that the last indication on that lens prior to infinity is 10m... but I am not talking about the indications on the lens, but real distances measured with a laser distometer. DOF is extremely shallow on high res DBs... IMO. Too, you will clearly see where the actual focus plane is as contrast in this area is very high. Consequently you also see the spread of DOF. So accurate focussing matters even for wide angles at distances below infinity. Again... IMO.
    Do you think the 70HR is sharp at 50meters when the lens is set to infinity (at f5.6)? Nope.
    The same goes BTW for my Contax lenses... it's not only related to the high performance (contrast) of digital LF lenses.

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    Re: A Comparison of Technical Cameras

    FWIW, if you want to do DoF calcs for focus testing on digital sensors, I think you need to use the sensor's pixel pitch as your CoC. If you do this, you'll have a CoC of 6u (0.006 mm or 0.00024 inches) for current MF backs, and I suspect you'll find that renders thin DoF's with any lens under 80mm at f8, at any distance under 10 meters. This is where a well-calibrated focus ring will pay for itself time over time...
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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by smei_ch View Post
    Close range is where these things really matter.
    Just my 5 cents.....
    Yes, close range is exactly where you can see the differences in accuracy.

    My image posted above was taken with a RM3D at approximately 1.28m away from the target, using a 100mm lens at F4. There is no way an Alpa camera can routinely nail focus like this without being tethered. And, I am only being kind by adding the word "routinely", since there is always that 1-in-a-million lucky shot.
    Last edited by David Klepacki; 10th September 2010 at 13:54. Reason: Poor math

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by David Klepacki View Post
    Yes, close range is exactly where you can see the differences in accuracy.
    you will see a mismatch at any distance below infinity ... the only difference at farther distances is that you have a bit more DOF. But you still see the focus spot.
    Actually I am finding to get accurate focus at close distances not so hard focussing on the groundglass. It depends on the subject... if there is sufficient light and the subject in question has enough contrast hitting focus on the GG is relatively easy.
    It get's much harder at farther distances when the magnification of the subject on the GG is too small... in particular distances almost but not quite infinity. It's frustrating when you shoot a building and it's actually not really soft but the tree in the foreground of the building is sharp as hell... and IMO there is no way to do this when focussing on a GG.

    edit: so another nice thing about the Rm3D's approach is that you can focus even on dark and/or very uniform surfaces (i.e. surfaces without texture and contrast)
    Last edited by thomas; 10th September 2010 at 14:34.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by Jack Flesher View Post
    CoC
    I never understood what circle of confusion actually is (though I have to admit I've always refused to read about it ). But what you say meets exactly my experience...

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by thomas View Post
    I never understood what circle of confusion actually is (though I have to admit I've always refused to read about it ). But what you say meets exactly my experience...
    That is the circle of confused photographers wondering why their pictures are not sharp.
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    Re: A Comparison of Technical Cameras

    David

    Thanks for starting the thread and also thank you for the time you have spent posting working examples of the focusing ability of the arca - very impressive

    for me your preferences underline the simple fact that every knowledgeable user has preferences in work flow and specific expectations regarding how each system choice delivers - each with at the margin relative strengths and relative weaknesses - depending on the photographer and the shooting situation - we arrive at different answers

    All this is useful for people considering choice.

    If I wish to walk around in fat light with a Schneider 35 or a 24 - I put my Hasselblad back on a 12 series Alpa a little hardrive in a pocket and shoot all day - being stopped occasionally by people asking what is that beautiful retro looking camera with the wooden handles and the crazy viewfinder

    for me it is much like shooting a Leica with a pocketful of TRX - very liberating and freeing - when I bought my first Alpa - Leica M didn't come in digital - and it was a great use of my Leaf back for editorial and reportage type street shooting.

    On a tripod a different type of shooting becomes possible - but as soon as you enter that 'space' - you immediately hunger for shift - and tilt and swing..

    so enter artec and now arca - these two are close competitors - but very different animals. the artec gives you everything in one package - the arca gives you a different version of nearly everything - just make sure for both they are on a tripod!

    I am not totally convinced about ground glass focussing on these systems - it is why I have never bothered with a ground glass for my Alpas - in the field - too often it is all too dark and when you add tilt/shift and swivel - really it is (for me) too often too hard to see what you are getting.

    I ask myself though- how can I see anything ever under any conditions with the arca? back on back off - too much hassle for me . the artec gives me a dedicated solution here .

    I like to see compose, frame - what I shoot in the field. In a studio if exactness is required - we all shoot tethered anyway.

    So it all boils down to what the photographer likes to use for what purposes - again.

    Thank you very much for the post - after Photokina I may contact Arca direct as it is down to one of arca or artec for me and the changeable back mount is a major plus for arca.

    pete

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by PeterA View Post



    I ask myself though- how can I see anything ever under any conditions with the arca? back on back off - too much hassle for me . the artec gives me a dedicated solution here .



    pete
    Pete- doesn't the rotaslide or kapture group solution eliminate back on back off?

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    Re: A Comparison of Technical Cameras

    Hi Terry,

    these add ons may well do the trick - and may even do it s well as the artec in built system - i don't know - that is why i am interested in user experiences.

    I have tested the artec and will do so again - but down here there is no access to arca. each layer of add on especially f matched to alternate suppliers adds another layer of potential risk/trouble when you live at the bottom of the planet -

    I look forward to any input from any real user about their experiences - one of the great benefits of forms like this.

    Now it is Saturday morning down here - grey skies so no happy shooting conditions - still I might just put the blad on the Alpa and see what I can get -

    Pete

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    Re: A Comparison of Technical Cameras

    Pete,

    First, with your setup I think either the arTec or the RM3D would complement your particular Alpa and MF cameras nicely, since either would add a new dimension to your shooting that gives you movements. If you do not plan on ever stitching panoramas, then the arTec will give you more lens movement. Otherwise, having a technical camera with rear planar movement is much easier to get better stitching capability.

    As far as focusing on any technical camera, there are only four different methods:

    1. GG on sliding back (same as arTec)
    2. GG without sliding back (back-off/back-on, same as Alpa)
    3. No GG, tethered live view (with MFDBs that support live view)
    4. No GG, scale focus guessing

    With the RM3D, the idea is NOT to focus using any of these four methods, but rather to focus based on measuring distance, and only use the GG for composition (with or without a sliding back). Furthermore, the GG is entirely optional with this distance measurement technique due to the Arca-Swiss EVF. So, this actually adds NEW focusing capabilities that are unique to the RM3D:

    5. No sliding back, No GG, untethered, EVF with distance meter

    Focusing is done by simply converting the measured distance to the index on the RM3D helicoid scale. This technique is extremely accurate, and the MFDB never moves in this case. Distance can be measured with a good laser meter (like the Leica Disto), or for shorter distances you could optionally use the Arca-Swiss ultrasonic device. The ultrasonic device has the added advantage of serving as a very accurate leveler.
    Last edited by David Klepacki; 10th September 2010 at 17:06. Reason: clarity

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by thomas View Post
    I never understood what circle of confusion actually is (though I have to admit I've always refused to read about it ). But what you say meets exactly my experience...
    I'm sure you're kidding, but in case you're not, OR for posterity, here is a simplified response...


    Circle of Confusion or CoC is an integral part of the optical formula for Depth of Field (DoF) calculations. Any point source of light is only rendered as a single point when it is in perfect focus, regardless of aperture or focal length or subject distance. Any time the point source is out of focus (oof) it becomes larger than a single point, it both gains area and looses brightness, and is then referred to as an "airy disk." At a certain diameter, which is now affected by aperture, lens focal length and subject distance as well as viewing distance and our own visual acuity, the airy disk no longer appears as a single point, but rather appears as a fuzzy spot. The maximum diameter we choose as "good enough" to still be considered a sharp point of light, is the "acceptable" CoC.

    By default, the absolute smallest "point" we can render in digital imaging is a single pixel. Therefore when viewing images at 100% magnification, the default acceptable CoC is equal to the pixel diameter of the sensor in question.

    Simplified, but hope it helps,
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    Re: A Comparison of Technical Cameras

    Interesting thread.

    Could someone please post a link, picture or explain now the Arca RM3D EVF works and what it looks like? For 2010 it's amazing Arca don't have a web presence to help sell their products. I've often thought that the Alpa SWA with CFV39 or equiv. P1 back would be just the ticket for me. I only need shift to control perspective. Tilt would be nice but I've never needed it in the past. It's the point of focusing accuracy that has always held me back. The Arca solution sounds interesting as I'm more often than not shooting subjects between 3 - 10 meters.

    As an aside, is there anyone here that regularly uses one of these systems to take environmental portraits? What about mid length portraits? I'd love to still be using LF sheet film and focusing on the GG for my work but where I live it costs over $11 to process a sheet of 4x5". Is the Arca / Alpa with digital back a viable replacement for a field camera that sees general use?

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by Jack Flesher View Post
    I'm sure you're kidding (...)
    no, I am not. Of course I've heard of it but in fact I never delved into it.
    Many thanks!

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    Re: A Comparison of Technical Cameras

    Regards . Jürgen .
    -----------------------------------------------------------------------------------

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by Jack Flesher View Post
    FWIW, if you want to do DoF calcs for focus testing on digital sensors, I think you need to use the sensor's pixel pitch as your CoC.
    Jack, I think your advice re the pixel pitch as reference for the CoC does make sense… apparently a lot of sense!

    Attached a scene from a backyard where I ckeck and adjust my split image screens of my Contax and check focus distances of my LF lenses.
    The image was taken with the 70HR wide open and was focussed using the groundglass and my 6x loupe, focus point is the water pipe.
    Distance to the water pipe is exactly 12m (based on measurement with laser disto).
    Now, when I look at the DOF of the actual capture… the 2.34m DOF according to the DOFmaster calculation (set to 7µm for CoC as I use a P45) seems to match the real outcome quite good...

    here's the 100% crop: http://tinyurl.com/33xe3nx
    Last edited by thomas; 11th September 2010 at 03:28.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by PeterA View Post
    so enter artec and now arca - these two are close competitors - but very different animals. the artec gives you everything in one package - the arca gives you a different version of nearly everything - just make sure for both they are on a tripod!
    pete
    you can use the RM3D hand held by removing the rotaslide... the viewfinder is much better than the Alpa !

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    Re: A Comparison of Technical Cameras

    thank you for the list-some points are important to me too, some are not so much (I am fine with just haveing Rodenstock), and few I am missing.

    Regarding the Artec: I have to say that with a relativly fast lens and one where you do not need to add a center filter focusing with the loupe and the screen of the Artec works pretty good. (could be different with slower lenses)

    There is one other advantage for ALPA: They have various different bodies- so you can choose depending which movements you want/need. Or you could add a TC for handhold/light/compact shooting. I really miss this from Sinar - something like a TC and even though of building it myself.

    A nice thing for Sinar is that I can use my back with the swivel-adapter. So I dont have to get the back of the camera at all when shooting.

    Rhe R3MD sounds very nice as well. It just wasnt available for so long.
    I still have not understood how to focus it-need to read somewhere again.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by t_streng View Post
    I still have not understood how to focus it-need to read somewhere again.
    The numbered ring is what you use for focus. It doesn't have distances but is very precise as it rotates multiple times. Each lens comes with a small card (which I've taken a photo of and store on my iPhone) which gives you a focus distance and the number to dial into for accurate focus at that point. This can be used in conjunction with the DOF scales that I have for the lens (on both the viewfinder and a chart made for me with the correct COC).


    Picture credit Arca Swiss - need to click twice (or three times) to clearly see numbers for focus.
    Attachment 35220

    Sorry not pretty but perfect size for my iPhone! Not sure why it didn't rotate but you get the idea.
    Since the ring rotates more than once, each lens has different colored lines on the mount which correspond to the color listed on the card....on this lens all except for the closest distance is in white. When you get to longer lenses you will use more of the full action of the focus ring. You can then use this in conjunction with traditional DOF/aperture to get your desired results.
    Attachment 35221
    Last edited by Terry; 11th September 2010 at 04:04.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by tjv View Post
    Could someone please post a link, picture or explain now the Arca RM3D EVF works and what it looks like?
    I am posting some pictures for you below. First, notice that the EVF has both portrait and landscape foot mountings to match the orientation of your back. Basically, Arca-Swiss provides three things with each lens that are unique to the lens focal length: (1) a focusing distance card (shown above by Terry), (2) a lens drum with DOF information that slides into the rear of the EVF, and (3) a numbered magnetic viewing mask with shift indicators that attaches to the front of the viewfinder.

    Here is how the EVF works. The top of the EVF contains the information about which numbered viewing mask is required to be mounted based on the focal length of the lens and the format of your back (film or digital). The EVF "zooms" to the appropriate magnification as you can see from the pictures. Any focal length from 24mm to 210mm is set by aligning the focal length value to the bottom of the fixed top part (i.e., the rear/bottom part of the EVF is what moves to zoom the view), and then applying the appropriate mask.

    The fixed front/top part shows what number mask is required for your particular digital back or film format. The leftmost column displays the range of digital back formats from 37x37 through 56x36 as well as film formats from 645 through 4x5. The rightmost columns correspond to the range of focal lengths. As an example, look at the image showing the top of the EVF fully extended. If you wish to use a 50mm lens and a 48x36 format back, then you would need to attach viewing mask #7. Or, if you wish to use a 210mm lens and a 48x36 back, then you would need to attach viewing mask #9. If you want to use a 35mm lens and a 48x36 back, then you would still use a #7 mask but you must also zoom the EVF by sliding it forward so that the 35 mark appears just below the fixed top part.

    Once the EVF focal length is set for your lens/back combination and the appropriate mask is attached, you can then compose your image. A shift composition is performed by sliding the mask up/down/left/right on the EVF. The mask contains small "holes" in it that can be seen when looking through the EVF. Each "hole" that you see in any x-y direction corresponds to 5mm of shift. For example, if you compose your image and see 1 hole visible on the bottom of the EVF and 2 holes visible on the left side, then you would then shift the rear of the RM3D by 5mm downwards and 10mm to the left (opposite direction as the mask) in order to match the back to your viewing composition.

    Once your image is composed, then you set your aperture and focus by measuring distance. For example, you can take a distance measurement with a laser meter. Then, you choose your f-stop based on your desired DOF from the lens drum. The lens drum (see the attached picture) contains DOF information based on the shooting distance and the f-stop for the lens being used. Finally, you focus the lens by using the focusing distance card, which indicates the appropriate RM3D helicoid setting based on the measured distance. Of course, shutter speed and iso are set according to the lighting conditions.

    That's it. I explained this perhaps with more detail than necessary, so it might sound complicated, but in fact this procedure all takes place as fast as your ability to compose the shot. However, to get really accurate focus, you must calibrate your lenses with your backs and create your own focusing distance cards and DOF information. This is a one-time-per-lens-per-back effort. This is what I did with my lenses and backs, and you can see the amazing accuracy that I now get from the test shot I posted the other day, without moving the digital back at all, i.e., without shooting tethered, without using a sliding back and without any ground glass focusing.
    Last edited by David Klepacki; 30th June 2013 at 21:29.

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    Re: A Comparison of Technical Cameras

    I swore I wouldn't get into this tempest, but what does EVF mean to you?

    In the non-Arca world, it means electronic viewfinder. My understanding of what Arca makes is that it is a variable (or adjustable) version of a non-electronic viewing/framing device. Like a "son of Linhof Multifinder." Is that wrong?

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    Re: A Comparison of Technical Cameras

    Wow, David. Thanks for posting such a detailed reply. The Arca certainly does seem like a supremely engineered piece of equipment. The EVF seems straight forward to use as well.

    Can anyone describe how the Alpa VF works in practice? If I'm not mistaken, it also indicates shift movements? Is it true the Alpa SWA is easier to hand hold and is more compact?

    In 2004 I was lucky enough to see Luc Delahaye's "History" series in Amsterdam. I remember reading the text in his book that he uses, among several other cameras like Linhof, an Alpa. I had never seen such big and detailed prints in my life. I see Delahaye is now listed on the Alpa web site as an official user. Not that I want to emulate his way of working, but his approach is close to how I'd like to use such a camera. The only thing that puts me off is the occasions I want / need to make portraits.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by stephengilbert View Post
    I swore I wouldn't get into this tempest, but what does EVF mean to you?

    In the non-Arca world, it means electronic viewfinder. My understanding of what Arca makes is that it is a variable (or adjustable) version of a non-electronic viewing/framing device. Like a "son of Linhof Multifinder." Is that wrong?
    Funny you mention this as I got all excited for a moment thinking my prayers had been answered with an electronic vf. That would be a brilliant inovation. Rather than use live view while tethering to a computer in the field a little VF plugs into the back to better assess framing and focus. Anyone listening? Phase One, Hasselblad, Sinar?

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    Re: A Comparison of Technical Cameras

    Framing and exposure can be done with a point & shoot camera. Jack posted about this on a thread he wrote about the Cambo. The camera that might be tailor made for this application is the Panasonic LX5. Small zoom range is 24-90 and you can set the zoom to step mode so the camera will stop at 24, 28, 35, 50,70, 90. Or a Micro 4/3 GF1.

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by stephengilbert View Post
    I swore I wouldn't get into this tempest, but what does EVF mean to you?

    In the non-Arca world, it means electronic viewfinder. My understanding of what Arca makes is that it is a variable (or adjustable) version of a non-electronic viewing/framing device. Like a "son of Linhof Multifinder." Is that wrong?
    Stephen,

    In the Arca world all it means is External View Finder, which in fairness is what they call it. We (forum posters who are lazy writers and texters) have shortened it to EVF...
    Jack
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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by TEBnewyork View Post
    Framing and exposure can be done with a point & shoot camera. Jack posted about this on a thread he wrote about the Cambo. The camera that might be tailor made for this application is the Panasonic LX5. Small zoom range is 24-90 and you can set the zoom to step mode so the camera will stop at 24, 28, 35, 50,70, 90. Or a Micro 4/3 GF1.
    Now that I think about it, an even better option would be live view using a descent LCD screen on the back... When pigs fly?

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    Re: A Comparison of Technical Cameras



    This is the Alpa viewfinder - it comes with masks for each lens you purchase. It has an inbuilt diopter as well as a nice bubble level ( which when using wides you can see as you compose hand held even) It is used only for framing and it isn't cheap - but it works elegantly for that purpose as well as adding a most important ingredient to the mix - retro cool.

    This is a free shooting machine - designed for those who like to shoot that way - hand held or on tripod. I don't need laser finders, light meters or prayer mats with this thing.

    I have even 'solved' the pinky poo issue that plagued my shooting with Hasselblad back on it - turns out the 'blad has pretty much the same issue as Phase One backs - needs waking up and needs to be shot within a specified time - so now I set back on flash sync, set time for 2 or three seconds, use the hasselblad external shutter release and make sure I take the pic within the 2 or 3 sec time period. After all this hassle - I get no pinky poos. Which makes me understand why Phase One is the most popular back and Alpa have designed the inbuilt cable release for the purpose - Leaf backs and Sinar backs don't need this rigmarole btw - and because the first back I used with teh Alpa was a Leaf - i couldn't figure out WHY I had "pinky poos" with 'blad.

    This issue is different to lens caste issues which you get with wides on any set-up and requires a white shading reference file t eliminate - the issue becomes more important the more one wishes to use movements - especially with wide angle lenses.

    * The information for Hasselblad users is on the Alpa site amd I got teh time to suss things out this weekend ( finally).
    Last edited by PeterA; 11th September 2010 at 20:41.

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    Re: A Comparison of Technical Cameras

    Man, that is one INSANELY cool camera setup! I'm a real sucker for good looking engineering, just don't usually have the budget to meet my tastes.

    So the general consensus is that Phase offers the best solution for use with a tech camera because of the wake up issues you describe? I've been thinking about the CFV39 for eventual use with an Alpa or such because I want to try avoid using my local Phase One importers at all costs. They're total clowns IMHO. That as the CFV seems good value for money. I write "thinking" because at this stage it's all "wishful thinking," but eventually it will happen. Just doing the groundwork research now.

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    Re: A Comparison of Technical Cameras

    Looks like Alpa very soon is going to present a Shutter release with integrated wakeup which will work with all backs that require it (PhaseOne and Hasselblad).


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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by smei_ch View Post
    Looks like Alpa very soon is going to present a Shutter release with integrated wakeup which will work with all backs that require it (PhaseOne and Hasselblad).

    Not all Phase backs need a wake up. I can use the P40+ on zero latency without wake up. The downside is battery life and potentially noise is you keep the back on for a long time.

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    Re: A Comparison of Technical Cameras

    I refuse to make photographs with anythign that looks 'daggy' drive anything that isn't super cool, or use a tractor with less than 120 horsepower - life is to short

    Yep Terry I think the 40+ sounds like a great back - tempting - but am waiting for Photokina announcements before moving..I can see myself picking up a refurbished or like new P45+

    The CFV is another example of Hasselblad doing me in - I bought my CFV11 new a couple of months before they 'discontinued' it an bought out the CFV - 39 for about the same bucks I spent on the CFV11 - great back, square chip - but only 16 megapixels

    I agree on importance of dealers - all manufacturers have this territory thing going on - which may be fine for the US - but down here you end up with one dealer thousands of miles away with the franchise for a continent the size of -ummm we the size of the US or Europe...ad we all know just how well 'monopolies work for the customer dont we?

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    Re: A Comparison of Technical Cameras

    Quote Originally Posted by smei_ch View Post
    Looks like Alpa very soon is going to present a Shutter release with integrated wakeup which will work with all backs that require it (PhaseOne and Hasselblad).


    Here my ALPA12SWA + SCHNEIDER SUPERANGULON XL 5,6/72mm + HASSELBLAD CFV-39 . The camera has the current built in "wake up" solution .
    A little release button in the left grip (for left handers only ?) which can not be seen here .
    Works fine for hand held . A bit tricky , when working from a tripod .
    Therefore I use the HASSELBLAD release cord H (3043370) when using a tripod . I am curious , what the new "wake up" will be .

    Attachment 35282

    I am leaving for Switzerland in about an hour for a couple of days . Unfortunately not ALPA-land . But they would not tell me anything about their PHOTOKINA new products anyway .
    Understandable .
    Regards . Jürgen .
    -----------------------------------------------------------------------------------

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    Re: A Comparison of Technical Cameras

    Peter, do C.R. Kennedy import Hasselblad in Australia as they do here in New Zealand? They are a small company here, and obviously can't carry a lot of stock, but are certainly better to deal with than our local Phase importer. Have you dealt with the Australian reps for Phase? I often think if I choose to take the plunge into MF land I should just fly to Sydney instead of Auckland to demo and buy, depending on exchange rates of the time.

    Quote Originally Posted by PeterA View Post
    I refuse to make photographs with anythign that looks 'daggy' drive anything that isn't super cool, or use a tractor with less than 120 horsepower - life is to short

    Yep Terry I think the 40+ sounds like a great back - tempting - but am waiting for Photokina announcements before moving..I can see myself picking up a refurbished or like new P45+

    The CFV is another example of Hasselblad doing me in - I bought my CFV11 new a couple of months before they 'discontinued' it an bought out the CFV - 39 for about the same bucks I spent on the CFV11 - great back, square chip - but only 16 megapixels

    I agree on importance of dealers - all manufacturers have this territory thing going on - which may be fine for the US - but down here you end up with one dealer thousands of miles away with the franchise for a continent the size of -ummm we the size of the US or Europe...ad we all know just how well 'monopolies work for the customer dont we?

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    Re: A Comparison of Technical Cameras

    TJV - C.R. Kennedy have the Hasseblad dealership - offices in Sydney and Melbourne. I haven't ever dealt with L&P ( Phase Dealers ) in Australia. It is a pity Leaf went with Phase Dealer in Australia - rather than the new Sinar Dealer - who is a fantastic bloke and a very knowledgeable photographer as well. Anyway I have my fingers crossed that Sinar brings out its own new big boy back in due course - especially after announcing their 85H multishot.

    Quote Originally Posted by tjv View Post
    Peter, do C.R. Kennedy import Hasselblad in Australia as they do here in New Zealand? They are a small company here, and obviously can't carry a lot of stock, but are certainly better to deal with than our local Phase importer. Have you dealt with the Australian reps for Phase? I often think if I choose to take the plunge into MF land I should just fly to Sydney instead of Auckland to demo and buy, depending on exchange rates of the time.

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