Sunday, November 14, 2010

Some success with drift alignment

I was able to to achieve 3 minutes of perfect alignment the other night! Jupiter stayed perfectly centered in the circle of my special alignment eyepiece, with no visible drift until shortly after 3 minutes. The longest exposure time so far that my friend Dave and I have attempted is about 40 seconds, so 3 mins would have produced some fairly decent results. Unfortunately Dave was not here(camera boy), so I was unable to do so.
What made this latest attempt more successful I believe was that after performing the drift alignment to the south(azimuth adjustment to the mouth) and then to the east(altitude adjustment to the mount), I repeated the south drift alignment again. I have read that after performing the second step, it throws the first step off a little. That seems perfectly logical to me because you are changing the location of the polar axis on your mount by adjusting either the azimuth or altitude.

Sunday, October 31, 2010

New Meade 12mm Illuminated Reticle

I just purchased this new Meade eyepiece with double cross-hairs for drift alignment imprinted on the reticule. It has several other lines and graphs but I will deal with those later.

I setup last night in my backyard, first performing a polar alignment using my mounts polarscope. I use to think using the polarscope alone with sufficient for astro-photography. Over 2 whole wasted nights of streaked pictures, I learned this was not so. Using just a polarscope for general observing is ok, but not for pictures! I did not have much luck using the drift alignment method last night. I started by looking for a decently bright star at my southern horizon. Because of trees and my house I have a limited area to pull off a polar alignment using the NCP and getting a decent look to my south because of the house. I was able to find a few faint stars to try with the new eyepiece somewhere around the celestial equator and the southern meridian. So with the RA tracking motor turned off, I let the star drift through the eyepiece and adjusted the eyepiece so that the star ran parallel between the cross-hair. It didn't take long, maybe 2-3 minutes, to see the star drift off to one side. I made an adjustment to my azimuth(can't remember which direction), and tried again. I tried a few more times with no real big success. It got rather late so I gave up after about an hour. All is not lost though and spirits are still high because I came away with some real experience in drift alignment.

I don't mind cloudy nights as much right now because with even a few breaks in the clouds I am able to practice aligning the mount and scope!