Zoom with K mount adapter , is it still sharp ?

[Mustafa Umut Sarac]

I have collected an Cosina and Tamron 70-210 zoom from APUG Free thread. Zoom was an Adaptall if I am not wrong and comes with an K mount adapter. I saw some picture galleries about that lens and it was extremelly sharp. But view from the finder was not extremelly sharp , Am I missing something ?

Umut

[Jeff L]

Which Tamron 70-210?
I have an SP 3.5 that is very good.

[PentaxBronica]

Check that the adapter is properly fitted?

I thought the Adaptall mount was purely a mechanical coupling (no glass), so it shouldn't make any difference which is fitted. However, if not quite correct then it could put infinity focus out.

Are the pictures sharp? I've never really been able to spot a sharp lens through the viewfinder, only by taking a magnifier to the negatives afterwards.

[Ian Grant]

It is a sharp lens, I know I checked it

Viewwfinders aren't that sharp particularly when they don't have dioptre adjustment to adjust for eyesight. Remember when you do use it because it's a telephoto zoom you need to use a faster shutter speedparticularly at the 200mm end of the range.

Ian

[Mustafa Umut Sarac]

I've never really been able to spot a sharp lens through the viewfinder, only by taking a magnifier to the negatives afterwards.

This is important information for me.Thank you.

It is a sharp lens, I know I checked it

Viewwfinders aren't that sharp particularly when they don't have dioptre adjustment to adjust for eyesight.

Thank you Ian , this is my first japanese and slr in 20 years. I had been missed to use telephoto. I am eating film with it and I am using with slow speeds because I ve been quite lazy to use my brain and I left everything to online photo editors.
I am listening calm radio and I feel sleepless and tired for last 3 days. What a torture and I am going to listen Iron Maiden after all

Thank you all ,

Umut

[PentaxBronica]

I have seen people say that they could tell a lens was soft as soon as they looked into the viewfinder, but I've never been convinced. It just isn't big enough. Maybe with a magnifying eyepiece but I've tried great lenses and ghastly ones, only noticed the difference when the prints came back.