Best Screen for 500mm F5.6

[paul_hagan]

Any opinions on the best focussing screen to use with the 500 mm F5.6 on a

Mamiya 645Pro?

I obviously use the standard split image/microprism and also use the A4 checker.

Clearly getting your eye in exactly the right position makes it possible to use

the split image/microprism but it is all a bit hit and miss. Would a Beattie

screen be of any value. I would much appreciate any input from anyone out there

who has had experience of another screen and how easy they are to focus with.

 

Many Thanks

Paul

[Ed_Ingold]

I find a plain ground glass the easiest to focus, even in the "old" days when all the available screens had split-prism "rangefinders". If possible, I get screens with a grid for alignment purposes. Gridlines also help you focus on the screen rather than the virtual image (otherwise a problem with "bright" screens).

[paul_hagan]

Thank you for that Edward. You are spot on with the comment about the ruled gridlines as a focus aid. I have tried it and the focus on film is perfect. Why is this fact not publicised more widely? I have only ever used them for more obvious applications, never thought of them for lenses like the 500mm f5.6. I was spoilt with the Nikon F2 screens- they offered one for every application - and they all worked!

Best Regards

Paul

[ondebanks]

A plain matte screen (or the A4 matte + checker) is definitely best on the M645 when using long telephotos. I changed to one when using my 300mm f4 Sonnar and it made a big difference in my focusing accuracy - even though the f4 Sonnar is bright enough to use the rangefinder spot & microprisms of the standard screen. I haven't used a Beattie type screen though, so I can't say how much better they might be. Maxwell screens are said to be even better than Beattie, BTW.

 

Ray