Originally posted by Lowell Goudge
From the photo, I would say definitely NOT pentax mount.
I own that lens in K mount, and the most telling thing I can see is that the rear shroud, or protection for apature activating lever is too deep and goes 100% of the way around the lens, it does not do this on a K mount.
Additionally, even with K mount, it needs to be slightly modified to fit a DSLR (the protection for the apature lever has to be cut down a little, it is a 10 minute modification detailed elsewhere in this forum)
I couldn't quite tell if the aperture protection ring goes all around or if it's one of the older vivitar versions with the wide protection shroud.
I already prepared my jackhammer, welding equipment, table saw, and a light saber to make that thing fit my camera, if it was, indeed, a wider version of the pentax mount

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