- The Chicago Astronomer -
Copyright 2004-2014 All rights reserved by Joseph Guzman Administrator/Founder/Chief Astronomer.
All text and images are the property of the original authors/artists and shall
not be used without permission.
Post by Al Degutis on Oct 25, 2004 19:19:07 GMT -6
Are you going to use the Canon, or Canon II (the next larger one), to do your asteroid hunting? I ask because aren't they Dobsonian mounted reflectors and don't Dobsonian's use Alt/Az mount instead of an Equatorial Mount? With an Alt/Az mount won't the field rotation make it difficult to "blink" for moving objects?
I came to these questions by way of my experiences this year with astrophotography. I haven't had much time to experiment with astrophotography and my relatively new 8" LX200 Schmitd-Cassegrain, but using it in Alt/Az mode I snapped some images of M57. Then I tried to stack them to improve the signal and reduce tghe noise and I could see first hand what is meant by field rotation. It was nearly impossible to rotate the image so that all the stars overlapped properly from each image using PhotoShop.
I found a software package that does a great job fixing the field rotation problem, Registar (not Registax) but it is rather expensive. I opted to get a wedge so I can mount the LX200 equatorial. Someday I'll find the time to set it up and experiment some more.
Thanks for the question. Right now the cannon is on a Dob mount but in the works is a GEQ mount. The 20" will be on a GEQ mount as well. Yes they use the Alt/Az but with the EQ mounts I wont have to worry about the field rotation and stacking the images. I also have drives on the Cannon for tracking so I dont have to many problems when it comes to stacking the pics. We are still working on the Ring we shot at the party. If we get everything else done we have to do then we will finish the pic then I will post it.
Ifyou have anyquestions about the exposure times for the astrophotography just let me know. I will help you.
[glow=blue,2,300]Stargazer's Departing Nightly on a beam of light searching for the Ultimate Wisdom of the Universe [/glow]