Quote:
Originally Posted by alocky
You can see some dark out-of-focus dust specs in the circular light patch, and the curvy 'v' shape looks supiciously like a caustic curve caused by a point source of light off-axis (to the left of your optic axis) and well within the focal length of the primary.
If it's a newtonian OTA is there a chance the focuser was pointed towards the moon? Or is there something bright and shiny in the field of view of the focuser when it is racked all the way in? I saw a similar phenomenon once on a newt where the manufacturer had thoughtfully placed a shiny chrome wingnut on the back of the secondary.
Another thing to watch is light getting in the viewfinder of the camera, if you're using a DSLR.
cheers,
Andrew.
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Yeah the dust should hopefully be removed now. Dust was on the sensor, somehow it got in there.
Speaking of the light - when i was imaging this the moon was close, but well out of range of the FOV. There are two things i can think of: Light from the house somehow got in (altitude was fairly high) or the moon. I will try putting something over the view finder of the camera as well.