Tokina 500mm Mirror Lens Focus Seized-up


longbo

Link Posted 23/08/2021 - 20:25
I've had a Tokina 500mm Mirror Lens for a while, but it's not been used for a couple of years. I got it out to try it with my K3-3, but the focus has seized solid. - I can't move the barrel at all. The lens has been in a drawer since last used, so it's not been dropped or otherwise abused.

Anyone know what could have happened? Does anyone have disassembly instructions so I can have a go at fixing it?

smc

Link Posted 24/08/2021 - 05:01
It may be dried lubrication in the focusing helicoid.


This might be helpful

https://www.flickr.com/groups/strobist/discuss/72157604235612536/


https://www.dpreview.com/forums/thread/2554136

Helpful

longbo

Link Posted 24/08/2021 - 05:30
Thanks for the info. I'll give it a go.

smc

Link Posted 05/09/2021 - 20:27
Any luck?

longbo

Link Posted 05/09/2021 - 22:30
smc

Thank you for taking the time and trouble to follow-up.

I found more detailed information about dismantling the lens on the Pentaxforums website and managed to take it apart sufficiently to gain access to the helical thread. There, I applied heat from my wife's hairdryer, which persuaded the thread to move, albeit rather stiffly. I have applied some silicon gease, hopefully to prevents it seizing up again, so hopefully it's fixed.

Regards
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