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10-17-2018, 09:10 PM   #1
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Focus adjustable c mount adapter?

Using shims on the Q c mount adapter to reach infinity focus. It is critical on the 3.2mm f1.8 fixed focus fisheye. A pain since the settings are lost if used on the Olympus m4/3 and then moved back to the Q.

Does anyone make a C mount with inner donut that can be screwed slightly in or out and then be locked via Allen screws? This would allow adjusting infinity once and never messing with metal shims.

10-17-2018, 09:53 PM   #2
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Could you glue the shims onto the adapter... Not as elegant but the shims would stay with the adapter
And the lens would mount elsewhere without them.
10-18-2018, 06:26 PM - 1 Like   #3
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I've found that I had to "bite the bullet" and buy separate adapters for each c mount lens, especially if I want exact infinity focus. On the Photodiox adapters you can take out the center ring and shim it inside. If you need to reduce distance, you can take the ring out and rub it flat over sand paper to reduce the thickness.

The simpler, non-adjustable c-mount to Q adapters usually have to be built up with shims, glued in place.
10-19-2018, 06:21 PM   #4
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Thanks for the ideas UncleVanya and cipher. Gluing the shims would work. Kind of clunky, but functional.

We need a Fotodiox style two piece adapter with removable center. Thread both pieces like a helicoid. User would turn lens until infinity focus is attained and then tighten side mounted set screws to lock the pieces in place. This would only allow 1-2mm of adjustment, but that should be enough for most cases. It would also require a c mount adapter for each lens. Manufacturers would love this.

Anyone know an adapter manufacturer?



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