After squeezing out the max from my 5D2 with the TSE 17 and 24 II lenses for architectural work and (mainly) Zeiss and Leica lenses for other kind of work I am about to upgrade to digital medium format. That's a big step with many possibilities, combinations that work and that don't, partly unclear future perspectives of systems, models and brands, so I have a few questions to you experienced guys who went this way for quite a time.
After evaluating the possibilities, my plan is to get a Contax 645 for handhold AF work and product photography and an Arca Swiss Rm3di for architecture work (plus Leaf Aptus-II 12).
Why Contax 645?
+ not too expensive and rather big choice of cam, lenses and accessory on second hand market
+ I just love Zeiss lenses:-)
+ particularely the Zeiss Contax 645 120f4 Apo-Macro :-))
+ possibility to use (Zeiss:-) Hasselblad lenses via adapter
- "dead" system (astonishing how alive a dead system can be)
- not all Contax 645 lenses good enough for 80 MP back (?)
- no 28mm lens available :-(
Why Arca Swiss Rm3di
+ modular system and mechanical quality is convincing (+ Alpa)
+ open system regarding lenses and backs (- Sinar arTec)
+ back is shifting up/down/left/right for shift and for stich (that's a +++ for me, don't know any other tech cam to offer this feature)
- no sliding back (only from Kapture, I would prefer the integrated Sinar and Hartblei solution due to higher precision)
- no website (that's just silly, I don't even know where to get the cam in Germany, I might have to travel to France ... which is actually no drawback, cause I love France;-)
Why Leaf Aptus-II 12
+ full frame 645 54x40mm (++)
+ file quality (from what I have seen up to now)
+ no micro lenses
+ (screen size)
- long exposure noise (?)
- camera adapter not exchangable (I would have to stick to Contax, which is a risk because the back is the highest investment of the whole set-up)
1 Hasselblad mounts
Is Hasselblad C, CF, CFE, F, FE the same bajonet mount? Meaning which lenses would fit via adapter to the Contax 645 cam body?
2 Contax 645 lenses
I assume that the Contax 645 35f3.5, 55f3.5 and 120f4 Apo-Macro lenses are "sharp" enough to make real use of the 80 MP / 5.4 micron Leaf back. Is that so?
Is the corner sharpness of the Contax 645 35 and 55 wide angle lenses on a 54x40mm back comparable good to the best Schneider/Rodenstock lenses in that focal range?
Did anyone use the Contax 645 80f2, 140f2.8, 210f4, 350f4 lenses with a high resolution full frame back like the Leaf Aptus-II 10 or PhaseOne 65+? Is such a combination qualitywise satisfying?
3 Schneider/Rodenstock lenses
Regarding the (wide angle) lenses for the tech cam I am not sure to go the way of Schneider symmetrical lenses or of Rodenstock retrofocus lenses (models with 90mm+ image circle in order to allow extensive shift movements).
+ corner sharpness shiftet mayby slightly better
+ less distortion, no mustache distortion
+ 28mm lens with 90mm image circle available
+ less/no magenta/cyan color cast towards edges (?)
So my questions:
Is corner sharpness shiftet better with Schneider XL 28/35/43/47mm lenses or with Rodenstock W 32/40/50mm lenses?
Do the Rodenstock lenses show any color cast towards the edges and do the Schneider lenses show strong cast?
Does the Leaf 12 back without microlenses perform better in this respect than the PhaseOne 65+?
How well does the Leaf software compensate such color cast (I think I read somewher that it does)?
(I did not recognize any color cast problem with the Canon 17 and 24 TS-E or with the Zeiss CY 21 on a 5D2 with micro lenses and the 17 with full shift means an angle of view like a 10.5mm lens, so that's pretty amazing. On the other side the Zeiss ZE 21 shows a cast and all symmetrical design wide angle lenses on a Leica M8/M9 with their very short distance from the back lens to the sensor and the steep out of axis angle of light produce strong casts towards the sensor edges. So I am wondering how serious this problem is with the mentioned MF lens - sensor combinations.)
4 Rodenstock mustache distortion
The mustache distortion of the Rodenstock lenses is not so easy to adjust in post, especially if the lens is used with shift.
As far as I know, Alpa and Sinar do offer software to compensate such, but Arca Swiss doesn't. Any other software with lens profiles available? Or Leaf/Capture One?
(Otherwise I would generate my own profile for Kekus lensfix PS plugin, like I did for example for the Zeiss CY 35f2.8 PC shift lens for the 5D2.)
5 Leaf raw files
Is it possible to open Leaf raw files directly in PS or is it possible to convert them first to DNG and then open them in PS because my workflow is (up to now) PS based?
6 Long exposures
How is the quality of the Leaf 10/12 files at ISO 80 and 160/200 at 15 sec. and 30 sec.? Still "very fine" or some long exposure artifacts?
I read that one might connect an iPad to a Leaf back and will get an "after view" or "live view" pic. How are iPad and back connected? Via WLAN or cable or bluetooth?
8 Back sliding
I am wondering that only Arca Swiss is offering the possibility to shift the back horizontally and vertically because this allow perfect shifting AND stiching while moving the lens side only is usable for shifting but not for parallax-free stiching. Is there any drawback of doing all shift movements (no tilt required) on the back side?
9 Cropping and focussing
Of course it is a major drawback that the MF backs still are CCD which does not allow live view. So the question is how to best crop and focus the motive? An optical viewer is too unprecise for cropping, does not help for shift movements and does not allow focussing. I like most the idea of having an integrated sliding back for back and ground glass (+ lupe) for quick and precise focussing. But to my knowledge this opportunity is only offered by a few tech cam manufacturers (Sinar, Hartblei, Gottschalt). So for cropping one needs to use a ground glass, I assume. But changing forth and back from ground glass to the back all the time seems very uncomfortable to me and will cause dust on lens back and sensor frequently. For focussing with wide angle lenses I think it's most convenient to use the hyperfocal distance for a given motive distance and aperture, for longer focal lengthes one might have to digitally measure the distance and work with trial and error.
In this matter your experience would be greatly appreciated.
10 Aperture and circle of confusion
According to optical physics, the circle of confusion in micron is roughly the value of the aperture. This means that at f 5.6 the circle of confusion is roughly the pixel size of the Aptus-II 12 back of 5.4 micron. Using f8 might still be okay but any more closed aperture should result in confusion circles which are larger than the pixel size and therefore it seems to be impossible to make use of the full sensor resolution at f11 and f16 or above. The lack of an AA-filter with the much higher sharpness per pixel compared to an AA-filter 135 FF cam compensates this a bit but still I am wondering that many photographers successfully use f16 or even smaller. So, which f-stop is really useful at high resolution backs like Aptus-II 10 and 12 or PhaseOne and 65+?
Sorry for taking so much of your time with such a long post!
Thanks in advance for your help and advice