Backfocus issue : Canon Lens With ZWO 2" EFW and ZWO Asi 183

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tazdevil71 avatar
Hello guys, I plan to use a Canon Lens with my cameras and A 2" EFW

I have 2 cameras : 2600MM and 183 MM.

I do not find issues for the 2600 : My lens + EOS lens adapter for 2″ Filter wheel + 2"EFW + ASI 2600 without tilt Ring –> it seems to be OK for 44mm back focus

But For The 183, i'm stuck : Lens + EOS lens adapter for 2″ Filter wheel + ASI 183 seems to be the solution, but i 've 2 issues :
- How can i mount the Asi 183 on the 2" Filter Wheel (M54 thread)
- If my calculations are good, i need to add 6mm more of Backfocus to achieve the 44mm. Am i right ? and then which ring must i add for those 6mm.

Thank you so much for helping.
andrea tasselli avatar
Get a M42 to M54 adapter and then add spacers as required.
tazdevil71 avatar
andrea tasselli:
Get a M42 to M54 adapter and then add spacers as required.


thank you 👍
was not sure that the 183 thread was a M42 one.
perfect
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