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Old 11-05-2012, 01:10 PM
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alpal
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Join Date: Jan 2012
Location: Melbourne
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Mario,
Quote:
Thanks for your comments on my image. As for a 2X Barlow, the doubling of image size would be offset by the doubling in the F ratio - this would mean that you'd need to expose the image longer to achieve a similar signal to noise ratio on the image. This would increase possible tracking errors, both in time and magnitude, due to the increase F ratio and magnification.

Thanks Mario,
I know that but my image scale would be 4 x the area & if
my tracking was good I'd be able to resolve more detail.
A good 2 x barlow is expensive so maybe I'll try to borrow one
just for the Sombrero to try it out.
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