M45 and with sub-optimal LP filter positioning

[paul]

All my previous M45 attempts were time limited under very poor conditions. This is the result of about 20x300sec @IOS800 with the 550D and 150mm newt:

The data was promising but as you can see it has a few issues; a result of experimenting with the Optolong L-Pro 2" fitted to the coma corrector (scope end). The stars are so bright that they generated "impressive" ? multiple donuts. 

I now have the clip version but my viewing opportunities for this object are limited. If I can get some time I may switch to other equipment.

[peter shah]

Posted by: @phar

All my previous M45 attempts were time limited under very poor conditions. This is the result of about 20x300sec @IOS800 with the 550D and 150mm newt:

The data was promising but as you can see it has a few issues; a result of experimenting with the Optolong L-Pro 2" fitted to the coma corrector (scope end). The stars are so bright that they generated "impressive" ? multiple donuts. 

I now have the clip version but my viewing opportunities for this object are limited. If I can get some time I may switch to other equipment.

sometimes if you turn filters around it you can eliminate reflections....later and higher end filters are handed and have an anti-reflective coating on one side... I'm presuming its a clip filter for a DSLR?...not so sure if you are able to turn those around.

[paul]

@peter-shah I suspected fitting the 2" filter on the coma corrector was not ideal but I had no other solution at the time. The donuts are all over the place relative to the bright stars so I suspect its reflection off the lens curved surface back on to the flat filter surface.

Yes I now have a DSLR clip filter which will hopefully fix the issue. (I will use the 2" filter in a filter draw in its proper place in front of my OSC when that gets its first light.)

[MarkAR]

Shame about the donuts, shows promise though.