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Old 28-09-2015, 07:03 PM
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alpal
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Join Date: Jan 2012
Location: Melbourne
Posts: 3,612
Quote:
Originally Posted by glend View Post
Did you ever do the Moon test with a piece of paper to see exactly where the focal point is located - as suggested a couple of times below? Seems like a better use of your time if you can pin it down before you start building mirror sliders.

No I didn't but with 40mm extensions on the mirror
I did get focus with an eyepiece.
It was 5 months ago & I didn't record the measurements.

With my proposed jig -
I could just put the focuser in the position that I want with the camera & RCC1 inside it -
making sure that the RCC1 is not too far inside the tube past the focuser.

You see - the RCC1 coma corrector sticks inside the tube with the focuser fully down.
This could be a problem when taking flats.
Putting it further back could cause vignetting.
I need to experiment at different points.

cheers
Allan
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