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Old 21-03-2014, 06:48 PM
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Shiraz (Ray)
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Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,918
Quote:
Originally Posted by Paul Haese View Post
I had to use a powermate 2.5X which reduces the image scale the further away you move the sensor. Bear in mind though that the image will get dimmer too.

I found that cameras with pixel sizes of 5um or thereabouts worked best with an SCT. Using a camera with smaller pixels and in particular very small can provide problems for you.
the rule of thumb shows that the optimum for the ZWO is f19 (= 3.75*5). Looks like you are using the 2.5 Powermate at about 2x to provide about f20 - so that's another validation for the rule . Minor point, but surely the image will get brighter as you move away from the 2.5 Powermate?

Interested in your comments on small pixels - what problems have you found?

Last edited by Shiraz; 22-03-2014 at 03:22 PM.
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