Digital requires more precise tolerances than film. A reply I received from Schneider;
"Basically the tolerance for digital imaging should be less than 0,02mm for the infinity adjustment otherwise you will get serious problems with the sharpness especially with wide angle lenses.
For focusing on closer distances the sharpness plane will move more or less, which is also not good.
You will have a very hard job when trying to get sharp images with a combination of a view camera and a sliding back, where fortune decides about image quality.
Best results will be achieved with Alpa or Cambo cameras which use a viewer and a perfect aligned lens helical mount combination."In comparison to above, film flatness should typically be around 0.2mm tolerance, a difference of 10x.
Thus if we speak of adjustment to such precise tolerances for optimum sharpness on high resolution digital back it seems what is required:
1. micro adjustment drives of lens movements and focus
2. means to view or with to see this preciseness of focus, whether teathered, or by a high accuracy focus mask (maybe ok on new IQ backs, maybe?), or a precision groundglass with groundglass perfectly shimmed to say within 0.01mm of sensor plane and a suffice magnifier
If we speak of using a medium format dslr on adapter to viewcamera, such too (dslr and adapter) have tolerances same as a groundglass, but if we also add stitching so does sliding adapter and its sliding plane, and we have more weight hanging on rear standard...
It also depends on the resolution of digital back used since higher resolution will magnify errors with blown up print size. For sliding adapter I have one for Mamiya 645 system backs for sale. It is a custom fabrication per my own design and precision made with a LARGE high quality Maxwell screen. The adapter works fine for lenses 72mm focal and longer on my 28MP Leaf. The sliding adapter is made to higher quality than cheap Chinese ones sold on Ebay. Material is duralumin, better than aluminum... Price is already what seems a steal...
http://www.luminous-landscape.com/forum/index.php?topic=51965.msg436529#msg436529Regards
Anders