I am just wondering if this lens would fit the K110D without any apdator needed? Yes it will fit your K110 or any other Pentax camera with a K mount.
On the aperture ring make sure the A (auto aperture) is set (you will need to press the little button by the side of it). You should see the aperture the camera is selecting in the viewfinder, if you have it on aperture priority (Ae) then you can alter the aperture with the thumb wheel. Not sure, I suggest you phone a specialist camera shop. Try callling Jessops. Good Luck. | 