Originally posted by vanakaru I got bunch of great old glass. Mostly Takumars and Helioses. But I get focus wrong with my k-5 pretty consistently. I have installed split-prism focus screen and I am very familiar with its usage from 30 years back.
Do I need to adjust the camera for each lens (actually I do not know how) or there is a problem with the camera itself?
All my new DA lenses focus right on spot.
There are a couple of problems with split-prisms and replacement screens.
Firstly, the split images need to be very accurately aligned for really accurate focusing.
Secondly - and this is a much more serious problem - when you install a new screen, you may well need to re-shim it for it to be in the correct position (and it only has to be out by a few microns for you to lose decent focus). Apparently, even the expensive screens can - and do - suffer from this. (Hopefully, all replacement screens will have their focus aids (i.e. split-prisms) harmonised with the screen itself, so you can focus accurately either using the aid or the screen itself - once you have the correct shimming.)
As I've said before on these forums, this is, for me, a major deterrent from installing my (cheap) replacement screen. So, I'll just have to continue soldiering on with the stock screen - though it certainly slows me down. For me, accurate manual focus requires a lot of effort (despite being very familiar with the techniques, from my film days).
As for using the green hexagon for focus "confirmation", in general, it just doesn't work anywhere near accurately enough (on my K-m, which autofocuses extremely accurately). However, it does seem to be able to do a reasonable job for some lenses, notably my 50s. This implies similar results for Catch-in-Focus.
So, pmastello, I would stick with the stock screen if I were you, and follow the advice given by that Godfrey chap!