Tonight again used my 6 inch F3.6 Cometracker meade Schmidt Newtonian. I shot the Horsehead Nebula, it was tracking very well on the Sampson mount, so went for full 10 minute shots. Final result is:
4 x 10 min shots for a total 40 minute imaging time with my Modded 350D and Baader UHCS filter
Higher res version here http://www.users.on.net/~josiah/mod3...lteredmmed.jpg
Processed with Iris and Photoshop. I used a single dark taken a few nights ago of similar length.
This is the deepest Horsehead shots ive taken thus far.
The odd bluish object top right is an internal reflection. )Corrector plate is not antireflection coated. The Cometracker is a cheaply made scope with a plate glass mirror but does the job
Scott
That's totally awesome. I can see the horsehead nebula extending right over to the left side of the image and down toward centre-bottom of the image - far more extensive than I thought.
I would have a guess that you might be able to remove that reflection by using a mask. Meaning that you use a less-deep exposure of the reflection to mask out the reflection in the deeper/final exposure.
Yes they sure do.
Thanks Paul. I used good old ISO 200, starting out with a 5 min shot but after trying 10 minute shots I continued with those as the filter darkens the sky somewhat. I did flat fielding but obviously that cant remove the reflection. I must try the mask idia. If I was keen Id remove the corrector plate and take it down to Chi Qin Co for an antireflection coating, but my budget allows for just the 10 inch recoat. Initialy I was just using the 6 inch while the 10 inch was down but I might keep using it fairly often even when the 10 inch mirror is back. One night I might try out my 400mm F3.6 lens too.
The other trick is to have the brightest star dead center and then it only reflects on itself. I can send you the Canon 300mm F2.8 Fluorite for an extended loan, as at the moment only works for Canon EOS. I would really like to see what you can do with it Scott.
