r.e.
19-Dec-2011, 21:49
I want to test two lenses for 8x10 coverage (which requires an image circle of about 315mm) at various magnifications and f stops.
The lenses are:
Nikkor 120mm AM ED f/5.6 (specs say 250mm at f/22 at 1:1)
Doctor/Docter Tessar f/4.5 210mm (specs say 250mm at f/22 at infinity, although Arne Croell has suggested that the real number may be 219mm)
I have already done some quick checks through the ground glass, but I would like to do a series of 8x10 photographs that will tell me exactly how these lenses are behaving, not just at f/22 but at larger apertures.
This will require fairly high magnification. About 2:1 for the Nikkor at f/22, not sure yet about the Doctor because my checks on it through an 8x10 ground glass have been cursory. But the latter, at f/22, is probably somewhere between 1:3 to 1:2.
I'm looking for suggestions on what kind of subject I should use to carry out these tests. Will it confuse things too much if I use a three dimensional object and, if not, what kind of object would be best? I'm interested in three dimensional objects because I'd like to see the concrete results for apparent depth of field as well.
The lenses are:
Nikkor 120mm AM ED f/5.6 (specs say 250mm at f/22 at 1:1)
Doctor/Docter Tessar f/4.5 210mm (specs say 250mm at f/22 at infinity, although Arne Croell has suggested that the real number may be 219mm)
I have already done some quick checks through the ground glass, but I would like to do a series of 8x10 photographs that will tell me exactly how these lenses are behaving, not just at f/22 but at larger apertures.
This will require fairly high magnification. About 2:1 for the Nikkor at f/22, not sure yet about the Doctor because my checks on it through an 8x10 ground glass have been cursory. But the latter, at f/22, is probably somewhere between 1:3 to 1:2.
I'm looking for suggestions on what kind of subject I should use to carry out these tests. Will it confuse things too much if I use a three dimensional object and, if not, what kind of object would be best? I'm interested in three dimensional objects because I'd like to see the concrete results for apparent depth of field as well.