 Posted: Mon Oct 09, 2017 1:30 pm Post subject: |
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marcusBMG wrote:
Nice pics, 28A is a good lens IMO, perhaps one of the best MF available covering that range.
If the Ev adjust is consistent - half to one stop - I wouldn't worry about it its pretty normal for me with my Pentax that some ev adjust is required. And can vary from lens to lens.
However what mount were you using Mark? That would be the first thing I would look at. Old PKA mounts in particular seem to be inherently a little "sticky". I wrote these pieces on PF about PKA mount inaccuracies.
Part 1.
Part 2
Part 3.
If the mount performs consistently without varying amount of over exposure with changing f stop on a variety of adaptall lenses, then that symptom can be due to a slightly sticky iris/aperture - not closing down sufficiently.
If you are using a camera that isn't aperture connecting to the adaptall lens, then it's the lens that needs scrutinising.
_________________
pentax ME super (retired)
Pentax K3-ii; pentax K-S2; Samsung NX 20; Lumix G1 + adapters;
Adaptall collection (proliferating!) inc 200-500mm 31A, 300mm f2.8, 400mm f4.
Primes: takumar 55mm; smc 28mm, 50mm; kino/komine 28mm f2's, helios 58mm, Tamron Nestar 400mm, novoflex 400mm, Vivitar 135mm close focus, 105mm macro; Jupiter 11A; CZJ 135mm.
A classic zoom or two: VS1 (komine), Kiron Zoomlock... |
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