M42 Problem

[robindurant]

Can anyone help me. I recently purchased a 6.3 Corrector to give me wider FOV when imaging and I am now getting this round disc of lighter background. Do I need a connector of some sort. I am fitting the Corrector direct to the back of the scope and my Canon 350D Camera to it via a approx. 4" long attachment for prime focus imaging.

Robin

[SteelRat]

Hi - can't answer yer question - bit out of my imaging league really (have no doubt you'll get an answer soon) - but am curious though; are you near any streetlights?

[robindurant]

No, but the Moon was fairly near and bright

[Kaptain Klevtsov]

that will be vignetting, no way round it except get a 2" focal reducer, then you most likely won't get enough in travel with the focuser. If you shorten the 4" bit you will do better as it will reduce the effect.

Captain Chaos

[SteelRat]

Love this forum 8)

[robindurant]

CC

Sorry I think that I have confused you all. What I have IS a 2" f6.3 Focal Reducer ( not as I stated a Corrector ) which is giving me the problem. The 4'' attachment is the one designed for connecting the camera to the scope for prime focus work, which I normally use but is too much in magnification.

[Kaptain Klevtsov]

The amount of reduction caused by the focal reducer is proportional to its distance from the chip in your camera, as is the amount that the vignetting effects. Reduce the FR to chip distance as much as you can, and the effect should be reduced or go away. 4 inches sounds like an awful lot, mine struggles at about one inch.

Captain Chaos