First, thanks to all who responded to my previous Alpa questions. Note - I have reviewed the Alpa site, so my concerns are things I could not find there.
Testing and shimming a specific digital back seems like the right thing to do on the surface. But, with the Alpa, the only time you know that the camera is in focus is when it is set to infinity. At any other focus point, it's an estimated crapshoot as to how accurately you are in focus. Even with a laser pointer, it's still not that accurate, as the laser pointer would have to be set precisely where the digital sensor is, plus one would have to rely on the accuracy of the lens' markings, which, no matter how accurate they are, still cannot be accurately assessed between markings. So, at best, you are only in the ballpark. I suppose one could continually shoot, changing the focus slightly, and checking the LCD, until precise focusing occurs. But this is not always possible to do.
I've considered using the Alpa ground glass, but...
1. Using ground glass means switching back & forth with the digital back. This opens up a big can of worms for keeping the sensor clean.
2. There's no mention on the website, so I presume the Alpa ground glass cannot be shimmed. So what good is it if you have a precisely shimmed DB? Focusing on the sensor and ground glass will most likely not match. Seems like being able to shim the ground glass to match the DB would be the best solution, but it's not an option, is it?
Furthermore, using the ground glass would enable one the see the effects of a polarizing filter. Something I use quite often.
I'd appreciate any comments, opinions, or tips on accurately focusing this camera. This seems to be my biggest concern.
FWIW - I shoot landscapes from a tripod only. For the past 40 years, I've owned and used a Hasselblad V system, most recently using a CFV 16 back. I'd like to upgrade, and the Alpa system appeals to me (other than the focusing ability). I've also considered using what I have, and purchasing a CFV50 back. I would like the shifting/stitching capabilities of the Alpa, not to mention the inherent IQ available.