Quote:
Originally Posted by barx1963
Hi Dennis
Yes the back focus is 105mm from the reducer. The Moonlight focuser adds 1.25" or 31.75mm so that gives a surface that is easy to measure from.
Malcolm
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Thanks Malcolm, I appreciate the update.
Have a look at this website where the Author has tested a C11 and it appears under average seeing conditions of 2 arcsec, the backfocus tolerance can be off by +-50mm for an APS-C sensor and +-20mm for a full frame chip.
https://www.innovationsforesight.com...cus-tolerance/
It makes me wonder how accurate we have to be?
Hope you get it sorted.
Cheers
Dennis