Europa wrote:
Also, have you ever used older photos and just add the newer exposures to it? It would be nice to add some more exposure time to mine instead of always starting over. Do the angles change by season at all? I did mine in July, I'm assuming too far away for the angles to have any affect.
They do change....but framing is an art that I have yet to master. In the case of this image.....I had to rotate the camera 90 degrees to get the elongation of the Galaxy to reach from corner to corner. I am a BIG believer in Astrotortilla for plate solving. I often use data taken over a period of several nights and if I had a permanent observatory - I would do this routinely. When I use data taken over several nights - it is because my kit has been left up for that time. Astrotortilla is a TIME SAVER. I never...never....never, ever do any alignments.
Here is my process
1) Setup mount - level mount base before ever putting the scope on.....I get it close although it really doesn't matter if it is level or not - but I am anal enough to level it anyway.
2) I polar align by using Polemaster - takes 5 minutes tops
3) I boot up either Stellarium or Cartes du Ciel (my favorite to us) and pick a bright star high in the sky and use CDC to slew to it. I do a rough focus which is needed for Astrotortilla to work.... I might add, rarely is the target star in the frame. Then I boot up Astrotortilla - and select SOLVE. It takes anywhere from 30 to 60 seconds but it will center the star - DEAD CENTER.
4) Now that I have a bright star in the frame.....I now refine my focus either using a Bahtinov mask or FWHM on Backyard EOS for Nikon.
5) If i am planning on shooting Andromeda - I will make active, Cartes du Ciel (CDC) and select M31 and slew to it. Then to make sure it is centered, I make active Astrotortilla and "SOLVE". Walla, M31 will be centered.
6) If guiding and at 150 second exposures I will...I make active PhD2 - I will make active the camera, mount, and calibrate. This was an important discover for me.....once PhD2 starts doing it's thing - I go TOOLS>MANUAL GUIDE - then I press on North 3 times and nudge the scope by 3 pulses....and I do West three times and nudge the scope west three pulses. This helps to move the mount's gears in the direction to minimize backlash. Then is selecte TOOLS>GUIDING ASSISTANT and select START. I let it run until I see where my polar alignment error is less than 1.5 arc sec. Then I let the assistant create the needed adjustment recommendations for backlash. Sounds complicated but it isn't.....once you start Phd2 and select those options you will see what I mean. At any rate, I accept their recommendations and apply them.
7) I start imaging - keep in mind that your target will move slightly from it's centered position because you nudged the mount using the Tools>Manual mode.
From starting polar alignment to imaging is 20 to 30 minutes.....prior to Astrotortilla it was an hour or so to get stuff working right....with alignment and finding targets my biggest time consuming issue.