Quote:
Originally Posted by alistairsam
Hi,
could someone help with the alignment process for analog setting circles on a Dob mount?
I have an 8" Dob mount, and if I print out a graduated scale on the base, where should 0 deg point to?
I have a digital angle gauge for alt, so that should be straightforward, but was not clear on the azimuth.
|
1. Get the base of your scope level. You need to find flat ground. Spirit levels help. The base of your scope must be fixed. (If it's on wheels you need a good way to lock them).
2. Find at least 2 bright stars.
3. Use software to find their current altitude and azimuth. Stellarium will do the job and is free. You'll need to make sure your position is set correctly.
4. Align the scope to one of the bright stars, so that you can see it clearly in the center of a medium power eyepiece. Read off it's altitude and azimuth and compare to your circles. If you have movable azimuth scales set them. If you don't rotate the base for azimuth, or note the offset and use it when you read positions.
5. Your altitude should correspond correctly. If it doesn't, go back to leveling your scope, or if you have an inclinometer zero it aimed at the star, then move your scope to negative what the altitude of the star is and zero again so that when it moves back to the star it moves correctly.
6. Repeat 3,4,5 for the second star. Hopefully you shouldn't need too much adjustment, if you do go back and repeat again for the first star.
Hope this helps.