Quote:
Originally Posted by gregbradley
FSQ106N used to have that type of artefact. Bright stars long the edge of the image had a black bar going through them like a wormhole.
Roland Christen said it was vignetting. FSQ106ED does not do this.
I would have thought it fits the definition for astigmatism where a star forms a line towards the centre of the image or at 90 degrees to it.
Are your spacings spot on?
A full frame sensor is a big ask for a small scope. In my experience with Taks they needed a 4 inch focuser to be happy with full frame no matter what the brochure said.
Its very impressive overall.
Greg.
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Some did Greg, mist don’t. I’ve seen FSQ85s and 106EDs do it as much if not more.
It’s the foil spacers in the objective. I mitigated it in one FSQ85 by making a very small aperture mask that masked off the foil edge (literally it became an FSQ84.5).
My current FSQ106N does not show any artefact even with an APS-C sized SX sensor. Might with a 16803 but that’s not going to happen
