Thomas,
[quote name='tho_mas' date='Apr 17 2009, 05:40 PM' post='277157']
I use a "Brightscreen" split image with microprism collar in my Contax. It's slightly brighter than the original Contax MFS-2 but not really as it needs some density to check depth of field.
But I didn't choose it because of brightness but to focus manually]
One reason for the brighter screen is so I can be able to more reliably tell when I do not need to go to f22 or lower. I had not considered the split image issue for critical focus and that is a very good idea. I see there will be a lot of technique improvement needed with the DB -- this was confirmed by my demo where focus that looked good in the finder was, on magnification, slightly and noticeably off. The split screem might be a good tool for me.
[Quote You have to rethink this as this is a receipt for soft images. Due to the 6.8micron pixels of the P45 diffraction starts at smaller apertures than f8. f11 is still perfect. At f16 you will clearly see some diffraction but from my point of view depending on the subject it is usable very good. Quote]
As for the small apertures, I know what happens even on film (I use very high-res film Velvia 100) but I still use them and would like to explain why, because I see many references to never using small apertures almost as if was a rule.
I'll start with this -- even at small apertures the lenses deliver high quality even though I agree they are noticeably softer than the optimum aperture. With my landscape work, I find depth of field far more important to the emotion of an image than critical sharpmess -- I often use very wide apertures as well for selective focus.
As for small apertures, I have found that an image which carries uniform sharpness front-to-back due to the small aperture (yes, even if softer overall than the optimum aperture could give) can be a much more powerful statement than one that is is critically sharp but has distracting obviously out-of-focus background areas. An example, a wide angle shot (45mm in 645) of wildflowers, with the close flowers right "in your face" and the distant mountains still sharp, gives a breathtaking sense of space, freedom and excitement. Getting the last detail of the dust on the petals, at the expense of blurring the mountains, just would not work the same way at all on an emotional level, or a visual one for that matter. This is my conscious trade-off. I use it without hesitation.
I am grateful that the Contax lenses allow a high level of quality, and that Contax actually gives me the option of f32 and f45, which most MF lenses do not. These are far from useless apertures. Try it, in the proper context, and you might be very happy with the impact.
Of course, whenever it suits my interpretive goal, I am a sharpmess junkie and always try for f 8-16 if I can. MF, however, carries less depth of field and the smaller apertures can become necessary.
I am looking forward to all the things I can learn here!
Guy
