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Forum: Pentax Camera and Field Accessories
12-30-2016, 08:24 PM
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I think "Official" refers to the "genuine" Pentax-brand adapter.
Steve
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Forum: Pentax Camera and Field Accessories
12-30-2016, 08:13 PM
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Thanks for the more better explanation than what I offered.
Steve
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Forum: Pentax Camera and Field Accessories
12-30-2016, 07:14 PM
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You may have have noticed that if you attach the adapter to one of your Takumars first and then attach it to the camera, it mounts like any other K-mount with the mount "tangs" tensioned by the small leaf springs on the body-side "tangs". As you unscrew the lens to unmount, the tension is released and the adapter drops slightly towards the body and becomes loose in the mount. The adapter behaves like that to ensure that the lens mount face is at the proper distance from the sensor for predictable infinity focus.
Many older German and Soviet M42 lenses have a narrow flange on the lens side that does not fully engage the mount face on the body. As a result, the adapter does not "snug up" against the tensioning springs and the lens rocks slightly in the mount despite being fully screwed onto the adapter. That is problematic both in terms of registration distance and lens axis alignment. There is also potential for light leaks. Some users on this site cope with the problem by placing slipping a hair band, o-ring, or rubber gasket over the rear of the lens to stabilize the lens and block potential light leaks.
What concerns me about your description is that you mentioned lubrication. The lens threads should mount smoothly when dry and should not require lubrication. If the threads have been damaged or are the wrong pitch*, the adapter will be difficult or impossible to attach to the lens.
Steve
* Sometimes people attempt to attach the M42 adapter to a T-mount lens (same diameter, different thread pitch) or a lens whose threads have been cross-threaded at some time. In both cases, the adapter may not fully spin on. There is also risk of damaging the adapter. Neither should be a problem for a CZJ lens in good condition.
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Forum: Pentax Camera and Field Accessories
12-30-2016, 04:01 PM
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If I am interpreting your fix correctly, it works by defeating the "snug up to register" feature of the genuine adapter at the cost of introducing sticky duct tape* into the lens mount. If the mount flange on your CZJ lenses are too narrow to engage the K-mount flange you might want to consider one of the fixes used by other forum users. I tried to find the relevant posts, but the common fixes are to use a rubber o-ring, fabric-sheathed hair tie, or thin rubber washer on the lens side to take up the slack. With any luck, one of those users will weigh in with the details.
BTW: Welcome to the Pentax Forums!!!
Steve
* I would be particularly concerned about tape residue making its way into the interlock mechanism catch that keeps the adapter in the mount. Both it and the mount itself are designed to operate clean and dry.
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