Unusual object near NGC3293?

[peter_4059 (Peter)]

I've been doing some testing of the ED80 and found this unusual object in a crop in one of my images - looks light a bright star with the sides pinched in but the other stars don't show the same effect. Anyone know what it is?

[Astroman (Andrew Wall)]

I think I remember reading somewhere that this effect is caused by little tabs in the light path on the ED80.. Cannot find a reference to it now. The object is a star, but the tabs have caused the cut outs. There may be other reasons, but I did read this somewhere.

[peter_4059 (Peter)]

Should I be able to see this obstruction through the lens? Looks all regular right through to the CCD - baffles are all perfectly round all the way down the tube

[h0ughy (David)]

peter, if you look at the little star to the lower left of the bright one you will see the same effect on it as well. obviously something in the optical train

[DavidU (Dave)]

Pete, have a look at the lens shim's of the objective.

[mill (Martin)]

My ED80 does the same on bright stars, see picture below of a crop of M45.
I even got spikes in it that i didn't ask for