Has anybody got any idea's on what i might be doing wrong?
I have a 2" BINTEL coma corrector apparently bases on a GSO deisign according to BINTEL.
They say to space it 53 to 55mm from the chip, this point is marked on the canon 1100D.
The image below is a spacing of 54mm, as you can see there's still coma. Iv'e tried other spacings, but it only makes it worse.
You've just got the DSLR connected to EOS adapter and straight to the coma corrector? Pretty sure the 55mm nominal spacing takes the 10mm or so of the EOS adapter into account, so that's all you should need.
I have an baader mpcc here at the moment. If I hold it and look through it in daylight, it is obviously in focus in the center and obviously out of focus around the outside. Does that GSO one look like that?
this coma corrector looks like the same as AstroTech model (designed by Roger Ceragioli). That one was designed to have much longer BFL distance (so an off axis pick-up prism style guiders, AO units and like could be used).
If that is true (and I'm pretty sure it is), the distance you should be shooting for is more like 75mm.