Many years ago when Hasselblad introduced their Acute Matte focusing Screen, there were other aftermarket brands of focusing screens available. Much hemming and hawing happened over the cost of the Acute Matte. We decided to try out the others in camera one day. Using a Hasselblad 2000FCW body, 100mm Planar lens, A12 film back one roll was carefully test exposed with the Acute Matte, another identical roll was exposed as in as much the same as the first roll. Color transparency results indicated the after market focus screen was slightly off focus while the Hasselblad Acute Matte was spot on and brighter using a PME prism as a viewing aid. That was the first and last time any deviation from OEM focusing screens was tried.

This is also why the insistence on the genuine original focusing screen during the Master Technika days and same instance on using only Sinar fresnel GG on a Sinar camera. Sticking to this Orthodoxy has produced zero focusing problems over decades of using these cameras.

All it takes is one wasted roll of film or wasted sheet of film due to what appears to be a simple thing, but the results are not worth the risk or believed-perceived improvement. Stay with the OEM when possible and respect the folks who designed and built the focusing system. More often than not. they really DO know what they are doing.


Bernice



Quote Originally Posted by Bob Salomon View Post

Then there was Mary Ellen Mark who had a similar problem with her a Rolleis. We went to SoHo and looked at her cameras, left her with loaners and brought them to service who couldn’t find a problem. Her complaint was that they were sharp head on but soft when angled.
Service sent them to the factory in Germany and they sent them to Zeiss in Oberkochen and they discovered a third party focusing screen was improperly positioned in the camera!