Newbei Questions: Arca Rm3di/Factum, IQ180 / IQ260-Ac, Macro, IR, RZ67 and others

[mark-vdi]

Hi, really impressed by exchange of info on this forum - has proven really useful - as such I am hoping you’ll be able to help me put. After ‘learning’ on APS/FF digital and having explored film medium format with a Linhof Technorama 617 + 72mm SK (what a piece of engineering!) and much exploring on the internet I am looking to invest in the Arca R-System primarily driven by drive to achieve best quality lenses on a ‘simple’ tilt system with good focus control on MF Digital. To this end the Factum with e-Cloud looks like it could really hit the mark. In the first instance I will be renting an IQ180 but am looking to invest in an IQ260-Achromatic longer term. So here are the questions a bit mixed and not in any particular order (and please excuse if a little naive) :

I normally do stitch panorama (via pano-head for example) in order to avoid distortion that is found for example at the edges of the 617 shots. Is the lens node for rotation the plane through the copal shutter? By the way I actually see an advantage of pano-stitching a tilted lens as opposed to normal vertical focus plane which also rotates the vertical focus plane . . .

My first choices for Lens with the IQ180 would be (Rodenstock) 40/70 as apposed to (32)/50/90 driven by LCC problems with the 32HR and much less(?) with the 40HR (as read elsewhere in forum . . .) Does this colour cast imply also a loss in ‘sharpness’ so that for best results (sharp across frame and no color-vignette to allow stitching) the 50HR would/should be ‘widest’ lens?

I will also be doing indoor ‘Macro’ work - single flowers etc. What would be a good macro lens recommendation to go with the Arca R-system assuming 90HR is not ‘long' enough’?
(I actually looked very hard at the RZ67 pro IID and if there had been a 32/40mm lens for this system that would tilt i would have been investing here instead and am still wondering whether the rz67 140mm Macro would justify this system on its own? - Price wise compared to a single Rodenstock lens it almost still works) For Info: One of the reasons for the IQ260-Ac in macro work is to obtain single shot B/W images through color plates to build later a ‘true’ color picture (every pixel sees every colour)

My understanding for the rz67 is that 50mm refers to 6x7 making it ‘equivalent’ to 46mm on 135 from the perspective of a 645 DB (due to crop relative crop of 645 digital back vs 6x7) whereas Arca R-lenses size is relative to 645 so that 50mmHR Rodenstock = 32mm on 135?

One other reason to get the IQ260 Achromatic is for the IR capability - I know where I lie here in the 135 world (Special Zeiss coatings - Coastal Optics 60mm etc. etc.) How are the Rodenstock lenses on the Arca for IR-transmition/ Focus / Central hot spot etc.? A better recommendation?

Many thanks for your help and time!, cheers, Mark

 

[dougpeterson]

I am looking to invest in the Arca R-System primarily driven by drive to achieve best quality lenses on a ‘simple’ tilt system with good focus control on MF Digital. To this end the Factum with e-Cloud looks like it could really hit the mark.

Factum is a great system for this. The eModule Cloud is great, just be aware that when you go to use tilt you'll need to use 100% review, presets, or our iterative focus mask technique to judge the Scheimpflug effect as focus is no longer a plane but a wedge.

In the first instance I will be renting an IQ180 but am looking to invest in an IQ260-Achromatic longer term.

Why not rent an IQ260 achromatic from the start? Seems better than judging by proxy using an IQ180 rental.

I normally do stitch panorama (via pano-head for example) in order to avoid distortion that is found for example at the edges of the 617 shots. Is the lens node for rotation the plane through the copal shutter?

Finding the nodal point on an R system with any given lens is the same as any camera system. Google can step you through it. It will rarely be through the center of the shutter (and then only coincidentally).

By the way I actually see an advantage of pano-stitching a tilted lens as opposed to normal vertical focus plane which also rotates the vertical focus plane . . .

I think you'll be impressed with how well shift-stitching works with the stitching-savvy lenses with a 60mp back. Lenses like the 60XL, 90HR-SW, 120ASPH, and 32HR have nice large and sharp image circles. See here for a chart of image circles.

My first choices for Lens with the IQ180 would be (Rodenstock) 40/70 as apposed to (32)/50/90 driven by LCC problems with the 32HR and much less(?) with the 40HR (as read elsewhere in forum . . .) Does this colour cast imply also a loss in ‘sharpness’ so that for best results (sharp across frame and no color-vignette to allow stitching) the 50HR would/should be ‘widest’ lens?

I think you're barking up the wrong tree here.

A 32HR does not have more color cast issues than a 40HR to any meaningful extent. Perhaps you're confusing it with the 28XL which, with a 60 or 80mp back can be hard to correct)? The 32HR is a phenomenal lens for the application you describe.

Here is a test we did with the 32HR. I can send you raw files, just email me.

I will also be doing indoor ‘Macro’ work - single flowers etc. What would be a good macro lens recommendation to go with the Arca R-system assuming 90HR is not ‘long' enough’?

I think you're assuming incorrectly. A 90HR with a tube(s) borrowed from your other R lenses (as described here) will get you quite close. I help our customers do exact distance and magnification calculations fairly frequently. While the 90 HR-SW is not billed as a macro lens for the use you're describing I think it would be an excellent place to start looking.

The 120ASPH is also exceptional, but in a starter kit I don't think it's one of the first two or even three lenses I'd recommend.

(I actually looked very hard at the RZ67 pro IID and if there had been a 32/40mm lens for this system that would tilt i would have been investing here instead and am still wondering whether the rz67 140mm Macro would justify this system on its own? - Price wise compared to a single Rodenstock lens it almost still works) For Info: One of the reasons for the IQ260-Ac in macro work is to obtain single shot B/W images through color plates to build later a ‘true’ color picture (every pixel sees every colour)

That's not a bad thought. But I'd start by testing the Arca to see if that would fit your use solo.

If you're interested in doing 3-shot color stacking for the hell of it (for the academic interest or the personal challenge) then go for it. If you're doing it for color fidelity I think you'll be frustrated. An IQ260 normal color single-shot capture in Capture One v7 has phenomenal color and you'll have a hard time building a color profile via 3 pure-color shots from the 260 Achrom which is more accurate in real world shooting.

My understanding for the rz67 is that 50mm refers to 6x7 making it ‘equivalent’ to 46mm on 135 from the perspective of a 645 DB (due to crop relative crop of 645 digital back vs 6x7) whereas Arca R-lenses size is relative to 645 so that 50mmHR Rodenstock = 32mm on 135?

See our Lens Visualizer.

FOV is purely dependent on sensor size and focal length. A 50mm on any platform behaves the same when used with the same sensor size.

One other reason to get the IQ260 Achromatic is for the IR capability - I know where I lie here in the 135 world (Special Zeiss coatings - Coastal Optics 60mm etc. etc.) How are the Rodenstock lenses on the Arca for IR-transmition/ Focus / Central hot spot etc.? A better recommendation?

This is a much more extensive conversation. I've worked with just about every medium format infrared-capable system (see this MF IR overview) and would be glad to work with you on picking out the right lenses. Also to help you pick whether an IQ260 IR would be a better option than an IQ260 Achromatic.

---

Also the IQ260 Achromatic does NOT currently have live view. Phase One has indicated they will release firmware which will enable Live View for this sensor at some point (it requires more-than-would-be-intuitive rework of the live view routine as the original routine deeply relied on the Bayer pattern of the standard backs). But I like to encourage purchases based on what's possible today or which are close enough to finished that I've personally seen working prototypes. That's not the case here.

---

You're on the right track though immediately starting with thinking about renting the system. Some of this is factual/objective stuff. Most of it is subjective.

 

[Paul2660]

You will still have color cast issues with a 40mm Rodenstock, just not as severe as with say a 43mm Schneider or 35mm Schneider. On shifts you will see much less magenta color shift with the 40mm, but still will have considerable light fall off, and thus need an LCC to help correct in post.

Light fall off on shifts IMO may contribute to color/saturation loss, but so much on detail sharpness. (unless you are considering an extreme shift of 25mm or so).

Capture One in Post processing does a really impressive job of pulling a lot of this color/saturation back with the Technical wide angle LCC corrections. However all is pretty much lost if you don't take the time to shoot the LCC.

Paul Caldwell

 

[RodK]

Two other comments I may have missed if they were made: An 80mp back limits your depth of field as you can stop down at least a stop further. So the 60mp backs are my choice, as well. The Rodenstock 40mm really needs a lens shade, so don't forget that. It has a tendency to display a central flare otherwise.
Oh, one more. The 120mm ASPH from Schneider does an exceptional job up close.

 

[Paul2660]

+1 one flare on 40mm a hood really helps for that.

Paul

 

[mark-vdi]

Many thanks for all the help and feedback:

Factum is a great system for this. The eModule Cloud is great, just be aware that when you go to use tilt you'll need to use 100% review, presets, or our iterative focus mask technique to judge the Scheimpflug effect as focus is no longer a plane but a wedge.

Definitely, which is why the focus mask will be so useful . . .

Why not rent an IQ260 achromatic from the start? Seems better than judging by proxy using an IQ180 rental.

Would love to but (un)fortunately the IQ180 is not coming from a regular camera dealer but from a repro. company that has the camera to supply to photographers who regularly use them for large image reproduction to be able to supply them with a system they might not otherwise be able to 'afford' and as such i am getting a deal which is a little different from 'standard market rates' . . .


Finding the nodal point on an R system with any given lens is the same as any camera system. Google can step you through it. It will rarely be through the center of the shutter (and then only coincidentally).

Thanks for link will follow this up.

I think you'll be impressed with how well shift-stitching works with the stitching-savvy lenses with a 60mp back. Lenses like the 60XL, 90HR-SW, 120ASPH, and 32HR have nice large and sharp image circles. See here for a chart of image circles.

This is what i am hoping but my panoramas are very wide . . . 'twist' stitching is unavoidable

I think you're barking up the wrong tree here.

A 32HR does not have more color cast issues than a 40HR to any meaningful extent. Perhaps you're confusing it with the 28XL which, with a 60 or 80mp back can be hard to correct)? The 32HR is a phenomenal lens for the application you describe.

Here is a test we did with the 32HR. I can send you raw files, just email me.

I had already found this review but the images are missing from the link if you could send me the 32HR image (via dropbox link) pre-adjustment I would appreciate it.

I think you're assuming incorrectly. A 90HR with a tube(s) borrowed from your other R lenses (as described here) will get you quite close. I help our customers do exact distance and magnification calculations fairly frequently. While the 90 HR-SW is not billed as a macro lens for the use you're describing I think it would be an excellent place to start looking.

The 120ASPH is also exceptional, but in a starter kit I don't think it's one of the first two or even three lenses I'd recommend.

Ok hadn't thought of looking at it that way - macro in real sense is pushing it a bit far more single / mutiple flower head rather than micro insect - more looking for flat focus plane

That's not a bad thought. But I'd start by testing the Arca to see if that would fit your use solo.

If you're interested in doing 3-shot color stacking for the hell of it (for the academic interest or the personal challenge) then go for it. If you're doing it for color fidelity I think you'll be frustrated. An IQ260 normal color single-shot capture in Capture One v7 has phenomenal color and you'll have a hard time building a color profile via 3 pure-color shots from the 260 Achrom which is more accurate in real world shooting.

To a certain extend I am coming from the Foveon world - truly spectacular image quality for the size of the sensor and 'totally digital artifact free' (other than the image is made of small uniformally colored squares which is what I am hoping to achieve from the above process - however absolute color values are a very tenuous if not foreign concept when dealing with the foveon raw images and the software is one of the most unstable (on OSX) pieces of software I have ever used. The color profile may not be perfect (shooting individual R/G/B plates) it will have its own character no different than if I were to use Ectochrome or Velvia film, and it will have no benefit in terms of luminosity resolution compared to the normal IQ260 but the final combined image should be able to reproduce much finer color on color transitions than an interpolating Bayer sensor.
By the way it would require 6 shots per image (since I would also need 3 grey card shots (one with each color plate) just to get exposure correct)


See our Lens Visualizer.

FOV is purely dependent on sensor size and focal length. A 50mm on any platform behaves the same when used with the same sensor size.

Ok good to know, info on Internet is a little confusing . . .

This is a much more extensive conversation. I've worked with just about every medium format infrared-capable system (see this MF IR overview) and would be glad to work with you on picking out the right lenses. Also to help you pick whether an IQ260 IR would be a better option than an IQ260 Achromatic.

Definitely get back to you on this one. i do not believe an IQ260 IR (= Bayer Sensor but no IR filter?) is the right option because I must assume that the Green/Blue filtered pixels cannot have the same IR transmission (if at all) as compared to the Red filtered pixels which I would assume are responsible for the majority of the IR image capture thereby considerably reducing the effective resolution of the sensor to IR as compared to the achromatic sensor. Of course if the lenses are suffering a high amount of IR diffraction then this may not be a noticeable but is not the result I would want to be aiming for (at least on a technical level) The bench mark I would want to use here would be putting a coastal optics 60mm UV-VIS-IR on the Nikon F adapter of the Alpa FPS and accessing a minimum 37mm x 37mm image circle = 38 MB (+) (6 micron Pixel) or 51 MB (+) (5.2 micron)

Also the IQ260 Achromatic does NOT currently have live view. Phase One has indicated they will release firmware which will enable Live View for this sensor at some point (it requires more-than-would-be-intuitive rework of the live view routine as the original routine deeply relied on the Bayer pattern of the standard backs). But I like to encourage purchases based on what's possible today or which are close enough to finished that I've personally seen working prototypes. That's not the case here.

---I would assume that no live view would be a knock out at this point.

You're on the right track though immediately starting with thinking about renting the system. Some of this is factual/objective stuff. Most of it is subjective.

True, the only problem is that I will have about 48 hours to learn to use it before I will be in ca. freezing conditions in Iceland ;-)

 

[mark-vdi]

Thanks for all comments in general and for heads up on shade and light fall off (a problem for pano work),

Cheers, Mark
Blauvista - Mark Ford - Digital and Film Photography

 

[Kevin Sink]

I have to echo Doug's sentiment on the 32 HR. It is without a doubt, the sharpest, best performing lens I've ever owned. It is also prone to flare or at least decreased color saturation, so I use a Lee Filter bracket with their wide angle lens shade. LCC's correct wonderfully, but not perfect when you are at the extremes. I routinely shift the lens 10mm in either direction (a 3 exposure stitch is often all you need: 10mm left, 0, 10mm right). The image quality from that resulting pano is superb, but it does start to fall off in sharpness and some distortion at the corners. You'll have to see what is acceptable to you. The lens is also VERY easy to use on the Rm3di. I have a short list of set-ups with tilt angles, and I can get a correct set up and shot taken in a very short amount of time.

I would also say the 60mm Schneider might be an exceptional choice for you. I'm thinking of buying it for the same reasons, and from what I hear it is one of the only lenses that can compare in sharpness to the Rodenstock 32mm.

 

[Chris Barrett]

A quick note: If you really want to do nodal stitching, I'd recommend getting a short rail for the Rm3d. I use one of my old Arca monorails anytime I need to get the R off center of the tripod. The R's were handily designed to mount up on all of Arca's view camera rails... part of why they have the most modular system available.

 

[mark-vdi]

Hi, thanks, for the tips. Was with Arca / Snap, Stuttgart today - very impressed with the R-System and very friendly! The Factum is very nice in its simplicity ;-)
Cheers, Mark

 

[Smoothjazz]

Doug,

Could you explain how the IQ 160 back works for infrared? How would it differ from the Achromat?
Thanks,

John

Factum is a great system for this. The eModule Cloud is great, just be aware that when you go to use tilt you'll need to use 100% review, presets, or our iterative focus mask technique to judge the Scheimpflug effect as focus is no longer a plane but a wedge.



Why not rent an IQ260 achromatic from the start? Seems better than judging by proxy using an IQ180 rental.



Finding the nodal point on an R system with any given lens is the same as any camera system. Google can step you through it. It will rarely be through the center of the shutter (and then only coincidentally).



I think you'll be impressed with how well shift-stitching works with the stitching-savvy lenses with a 60mp back. Lenses like the 60XL, 90HR-SW, 120ASPH, and 32HR have nice large and sharp image circles. See here for a chart of image circles.



I think you're barking up the wrong tree here.

A 32HR does not have more color cast issues than a 40HR to any meaningful extent. Perhaps you're confusing it with the 28XL which, with a 60 or 80mp back can be hard to correct)? The 32HR is a phenomenal lens for the application you describe.

Here is a test we did with the 32HR. I can send you raw files, just email me.



I think you're assuming incorrectly. A 90HR with a tube(s) borrowed from your other R lenses (as described here) will get you quite close. I help our customers do exact distance and magnification calculations fairly frequently. While the 90 HR-SW is not billed as a macro lens for the use you're describing I think it would be an excellent place to start looking.

The 120ASPH is also exceptional, but in a starter kit I don't think it's one of the first two or even three lenses I'd recommend.



That's not a bad thought. But I'd start by testing the Arca to see if that would fit your use solo.

If you're interested in doing 3-shot color stacking for the hell of it (for the academic interest or the personal challenge) then go for it. If you're doing it for color fidelity I think you'll be frustrated. An IQ260 normal color single-shot capture in Capture One v7 has phenomenal color and you'll have a hard time building a color profile via 3 pure-color shots from the 260 Achrom which is more accurate in real world shooting.



See our Lens Visualizer.

FOV is purely dependent on sensor size and focal length. A 50mm on any platform behaves the same when used with the same sensor size.



This is a much more extensive conversation. I've worked with just about every medium format infrared-capable system (see this MF IR overview) and would be glad to work with you on picking out the right lenses. Also to help you pick whether an IQ260 IR would be a better option than an IQ260 Achromatic.

---

Also the IQ260 Achromatic does NOT currently have live view. Phase One has indicated they will release firmware which will enable Live View for this sensor at some point (it requires more-than-would-be-intuitive rework of the live view routine as the original routine deeply relied on the Bayer pattern of the standard backs). But I like to encourage purchases based on what's possible today or which are close enough to finished that I've personally seen working prototypes. That's not the case here.

---

You're on the right track though immediately starting with thinking about renting the system. Some of this is factual/objective stuff. Most of it is subjective.