Recently a fellow member sent me a message about using the Pentax-M 400 f/5.6 on the K-5. We both currently own this lens and are quite familiar with its performance on the K10 or K200D 10MP sensor, but I hadn't yet tried it on the K-5. So I headed out with the old M400 mounted to see how it would go with the apparent increased performance of the K-5.
In summary, I'm quite impressed with the performance of this old 400mm on the K-5. It's only quite a quick comparison, but I do feel that the usefulness of this lens has been improved. Below I have included some of my examples at 400, 800, 1600 and 3200 ISO. If you would like to see what the image looks like at full size (100%), please click on the image and then right click and select "original" from Flickr.
I would also like to invite anyone else who has used old telephoto lenses on the K-5 to compare notes and post their examples. And please feel free to let me know what you think.
Here are some of my examples.
M400 @f/16 400 ISO
M400 @f/16 800 ISO
M400 @f/16 1600 ISO
M400 @f/16 3200 ISO
Lastly I took a shot at 80 ISO just to compare. Unfortunately I missed the focus slightly so it's not quite as useful as the other shots.
M400 @f/8 800 ISO (slightly out of focus)