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Old 16-09-2009, 07:29 PM
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bloodhound31 is offline
Join Date: Aug 2006
Posts: 4,628
Originally Posted by Gama View Post
That big blob Baz, is, believe it or not, a tiny, tiny piece of dust or similar spec on the filter window of the camera. Its just that big due to the distance the shadow is cast.

Problem is it may have been clean at the time of testing, but shipping causes many bumps, etc. This can dislodge a speck from somewhere else to fall on somewhere where a shadow is caused on the sensor.

Even camera lenses get dust in between them.

The smaller ones are, yes, Theo, but the large one appears to be a tiny inclusion in the glass. When light is shone on the chip, this tiny fault reflects back.

If a bright star is in or near this inclusion, a curved diffraction spike emanates from the point source.

As promised, here is a full frame JPG of a flat from the chip, followed by an unprocessed JPG single-sub light frame.

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