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Old 28-11-2015, 12:38 PM
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Atmos (Colin)
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Join Date: Aug 2011
Location: Melbourne
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Quote:
Originally Posted by apaulo View Post
Atmos

The correct distance of the qhy9m is 17.3mm and you have to add the back focus of the filter wheel also, which measures 20.6mm so a total of 38mm

The WO website suggests the distance required is 73.5mm for the WO P-flat 4 and the WO flt110.

Hence 73.5mm - 38mm is close to a 35mm spacer required.

The question is still un answered though
"Is the total distance of 73.5 mm from the end of the p-flat 4 to the CCD face or is it the variable setting on the P flat 4?

AS for the thinkness of the filters themselves, not to sure about that one...

Regards Paul
Haha so now I have four figures from numerous different locations across the web!

As for the filters, it is correct that you add a third. So with a set of Astrodons I had to add another 1mm to the calculation. Do my flattener effectively went from 54.8mm to 55.8mm.
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