- The Chicago Astronomer -
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Modded Canon T3i dslr + coma corrector on 6" Astrotech imaging newtonian and Celestron AVX mount. Auto-guided with SSAG and PHD.
First pic: 1 hour and 15 min. total integration Ha 12 nm filter OIII 12 nm filter 670/30 nm filter for SII but also picks up a little NII(nitrogen 2 at 658.4 nm and negligible Ha at 656 nm) Ha OIII 670/30(as in RGB)
Second pic: 30 minutes Ha integration Ha 12 nm filter
Question for you... When using the SSAG does precise polar alignment matter? Would setting up the mount with a polar scope suffice for the length of times you are dealing with?
With the AVX, sometimes I just make sure that Polaris is in the center of the hole where the polar scope should be and I get good results with the SSAG. So, without precise alignment I can do 10 min. exposures with good results-no need for a polar scope.
For best results, I even level the tripod, make sure that Polaris is in the center, balance the scope(a little east heavy) and Polar Align with any available star that is not too close to the horizon(ASPA). It is critical that you do a precise ALL STAR ALIGN for ASPA accuracy!
All this sounds complicated but is not! After you do it 2 times it becomes second nature! Calibrating the SSAG is a breeze too!
As a precaution, I limit exposures to 10 minutes(to avoid star elongation).