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Old 15-09-2021, 05:19 PM
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Ryderscope (Rodney)
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Join Date: May 2006
Location: Glanmire, NSW
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Quote:
Originally Posted by PRejto View Post
Very nice!

I'm curious about the 8 spikes on the brighter stars. Is that a microlens effect on the CMOS? Or, is it the inbuilt diaphragm of the Canon lens?

Thanks,
Peter
Yes, the diffraction spikes are caused by the diaphragm in the lens that is used to step down the aperture. I have a step down ring which screws into the 72mm lens filter thread on the front of the Canon lens which reduces the aperture to something approaching an f6.0. I will fit this when I finish getting everything else working ok. It is definitely necessary to step down the lens as the stars around the edge of the field are pretty awful with the lens wide open.
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