Author Topic: Focus adjustment  (Read 12816 times)

chrissie_c

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Focus adjustment
« on: December 19, 2020, 02:39:41 AM »
I'm using exclusively Nikon-mount (Tamron, Sigma and a couple of real Nikon) lenses with a FotoDiox 'pro' adaptor (the one with the blue stop-down ring) and have been having focussing oddities so I decided to try out the back-focus adjustment as detailed in the manual.

I started turning the mount with the lens focussed on infinity and pointing at a remote tree as described. I turned it and turned it and turned it and turned it. It was getting nearer, I could tell, but it was sticking quite far out of the camera now and when it was very near (but still not right) there must have been a whole centimetre of thread visible! I thought leaving it like this might not be a good idea, given the weight of most of the lenses and the strain that must put on the mount, so I put it back in again and gave up. I'd rather have erratic focussing than a broken camera.

Was I doing something wrong? is there another adjustment I can make or a shim I need to put in place to get decent focussing - or even a different Cmount to Nikon adaptor? My main problem at the moment is the 'infinity' is at the point marked about 2m on the lens, yes really,  and I can't get very close to anything with it in focus.

How are other people with Nikon lenses getting on?

Nikon1

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Re: Focus adjustment
« Reply #1 on: December 19, 2020, 02:47:00 AM »
Do you use this 5mm Spacer, that came with the Camera, in between the Camera Mount and The Adapter? It is needed to be in there, otherwise your Flange distance will be way to short, and you will need to do things like Screwing the Adjustable mount out way too far, because those 5mm are missing. See Images.
« Last Edit: September 17, 2023, 09:08:58 AM by Nikon1 »

Nikon1

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Re: Focus adjustment
« Reply #2 on: December 19, 2020, 02:50:35 AM »
Camera Mount is an CS-Mount, Adapter has an C-Mount. For further information about the Differences between those two and Spacers see:
 https://en.wikipedia.org/wiki/C_mount

chrissie_c

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Re: Focus adjustment
« Reply #3 on: December 19, 2020, 07:51:21 AM »
AHHHHHHHHH!!!!!

I didn't realise there was a spacer on the 'old' Fotodiox, so when the new one arrived I just replaced the whole thing.

Now I've managed to get the spacer off and put it on the blue Fotodiox and it's fine after a little reacalibration.

Thank you :)

Nikon1

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Re: Focus adjustment
« Reply #4 on: December 19, 2020, 07:52:21 AM »
no Problem!