I just got one of these, its the de-clicked aperture. I used to run Pentax equipment until my camera sensor died. I also collected old glass because you could still use them on the Pentax DSLRs. We just got back from taking a walk and I took so many pictures I drained the battery on my D50.

Here are some of the samples CLICK Should be the top post where you can see a pic of a satcom dish in the comments.

I am really digging the adapter for my pentax lenses. It has its draw backs but my Tamron 70-300mm that I paid good money for a decade ago is back in the stable. I have a loaner 70-200mm zoom and its just not as sharp with the adapter.

50mm F2.8 prime
18-55mm Kit lens from my dead pentax ist-dl
70-300mm Tamron Zoom

And I can use the lens from my Nikon D3200 on my D50 and use all these Pentax lenses on my D3200 as well.

Adapter issues:
Very soft and distorted at widest aperture with the 70-200mm Zoom from the 1970s. Mildly soft and ethereal with the 50mm Prime, just soft enough to be useless with my other lenses (Does not look intentional, i can work with distortion if its cool looking). If you stop it down a bit the softness clears up.

Next issue is a bright spot. This adapter has a lens on it. At F22 you notice a large bright spot in the center of the image.

You have to manually set the aperture after focusing. In case your lens doesn't have an aperture selection ring the adapter has one built in and it will activate your aperture for you when you turn it, but you have to guess what Fstop you are at, there are no designations. .

I feel like a filmy again!

Basically you can't shoot at 2.8F with the 50mm prime, you have to shoot at 5.6F, and you can't stop it down beyond 16F or you get that bright circle. Its less of an issue with my Pentax AF lenses, but its still there.

With the old lenses I have, its tragic unless I am deliberately using the flaws as an effect. With my newer Pentax lenses, its better, but still there. You basically lose range and sharpness.