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04-29-2016, 02:11 AM   #16
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I should specify that I have the Manual Focus A* lens. The FA* is also a star optic, so it should be also very good optically !
The comparison with the 90 Macro was Manual Focus versus Manual Focus (D FA90 / 300A*) - I made also an automatically focused shot with the D FA90, and in comparison with the really carefully manually focused shot the AF shot is a wee bit sharper than the manually Focus shot. Strange, but good to have a really exact AF :-)


04-29-2016, 07:22 AM   #17
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QuoteOriginally posted by Hart-Worx Quote
Would be perfect. I tested everything. maybe mine is simply broken. at f8 it produces realy wesome results. focus is not the Problem. also tried manual focus.
Hi Hartmut,
I am very new to Pentax glass but even so a little surprised how soft it looks wide open after you saying at f/8 the results are awesome. Just a feeling and of course I could be wrong but as mentioned earlier in the thread could the lens need a little AF fine tuning - it could explain the large difference you are seeing from f/4 to f/8.

I hope you do not mind but I just tried sharpening the image and the result just seems to point to the potential for AF fine tuning to be a little out - of course it could be your sample but IMHO until you try AF fine tuning you will not be sure
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04-29-2016, 05:37 PM   #18

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It is rare to see large variation in optical performance right out of the factory. More commonly, one sees variation from copy to copy in used lenses. If they get banged around, lens elements can move slightly and can become de-centered.

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300mm f4 sharpness, 645d, 645z, 90mm, camera, dfa, f4, lens, medium format, pentax-fa* 645 300mm, shot, smc pentax-fa*
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