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Forum: Pentax DSLR Discussion
01-06-2010, 08:34 PM
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Forum: Pentax DSLR Discussion
01-06-2010, 08:18 PM
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Unfortunately, yes (1.02).
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Forum: Pentax DSLR Discussion
01-06-2010, 05:13 PM
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A story before getting to the subject: I dropped my case from a half a meter fall. It is a tamrac case with my K-7 (with a tamron 18-250 attached + grip), an 80-320mm, a Metz flash and some filters.
It was enough to slightly "bend" the lens mount (not visible with a naked eye). Body mount was fine. I´ve got 4 days into complete madness before figuring out what happened. Symptom: camera would take low light pics ok, but daylight (sunlight) pics *always* overexposed.
When I carefully examined the tamron 18-250, I´ve found that the mechanical aperture level was stuck: it is supposed to return to the closed position.
Simply took the lens apart. After removing the screws from the lens mount, I saw that the bend was keeping the inner aperture ring from running (friction).
Now, to the point: remove the lens and check the mechanical aperture leveler. If you carefully move it, you´ll see that the aperture blades will open. Release it and it should return to the closed position. If it is not returning by itself, then I think that might be the problem.
Good luck!
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Forum: Pentax DSLR Discussion
01-06-2010, 03:00 PM
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Greetings,
I recently bought a Pentax K-7, a Tamron 18-250 and grip. My idea was to replace my old K10D, used with the default Pentax 18-55 and a Sigma 28-200 (that came from my old MZ-7 days). As soon as the K-7 arrived, I sold the k10d.
To be honest, pics are ok, and I think that overall IQ is nice for the price range and for the fact that this glass covers from 18 to 250mm.
But I´m having a strange and annoying problem: autofocus. If I let it autofocus, no matter if I´m in low light or sunlight, stopped down or not, 18mm images are always blurry and out of focus. It gets gradually better up to 65 to 70mm, where the problem seems to disappear.
Not that the glass isn´t sharp if I manually focus it, the problem is AF: it always "thinks" that the subject is closer than it actually is, while in th 18mm to 65 / 70mm range. Tried spot focusing, stopping down etc. Tried a tripod. Same results. Turning SR off improved results just a bit, tho.
I also tried fine tuning AF from the K-7 menus: tried up to +10 and -10. No deal.
Fact is, if I autofocus, it is clear, just by using the distance guide printed in the lens body, that something is wrong.
I was wondering if anyone came across the same behavior. I´m about to return the tamron and get a Sigma 18-250. I don´t have a Pentax body around to make more tests but I don´t know for sure if the problem is with the glass or body.
Any ideas, thoughts, suggestions ?
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