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Pentax K-Mount Lenses and Lens Accessories

various Pentax lenses

Lens Data and Descriptions

Measured Resolution Numbers

Two serious Pentax users have undertaken the tremendously demanding job of testing the resolving power of variuous Pentax lenses. This is a complicated task with an astonishing number of variables, and conduxting multiple test so that the results are meaningful requires choosing one fixed value for each variable and holding it constant over all tests.

Our two testers work independently, and for some of the setup variables they have chosen different values from each-other. As a result, it is safe to compare the resolution tests by the same tester, but no conclusions can be drawn by comparing the resolution results produced by different testers. Still, the data is very valuable, and a summary of the resolution tests is presented here. The full details can be found on the Web pages of the individual testers.

Lens-Related Adapters

i = Pentax never produced a K-mount adapter (one that allows the use of K-mount lenses on screw-mount bodies) probably due to the fact that such a device would be of little use. Since the diameter of the K mount is larger than that of the screw mount, a K mount lens will have to be mounted in front of the screw-mount body, and the adapter will act like a short extension tube. Because of this, the focusing scale of the lens will not be correct, and the lens will not be able to focus to infinity.