Wednesday, November 19, 2008

11/18 Imaging Session

Last night was absolutely lovely! Excellent transparency (5/5) very good seeing (4/5) and a dark sky that remained so until around midnight when the Moon rose. I rocked up to the local observing spot after work and stayed for several hours where I tried out a slightly different astrophotography configuration.

As noted in a prior post, I have experienced issues trying to couple my Nikon D40 to my William Optics Petzval 66mm refractor. After a lot of ordering different parts I got there and thus far have been able to test with the Moon. So last night I was finally able to test the configuration atop my LX200 SCT. The setup was stable enough. The guide rings I have are tricky, and you have to work hard to make sure there's no wiggle movement. A couple of times throughout the night, after slewing, I noticed the 66 had shifted position somewhat. Anyway, being able to reach focus, I targeted a few objects:

a. Retake of M31
b. M45 Plieades
c. Double Cluster

My main focus was on M31. Some people seem to have no issue capturing gorgeous images of this galaxy. I took about 20 three minute exposures over the evening, and also shot a series of dark, flat and bias frames. At time of writing I am still processing the image and will post it here when done.

The flat images I took are all wrong, however. My exposures were too long (20 seconds) whereas they really only should have been around .3 to 1 second exposures. As a result I am still seeing some vignetting and dust mites on my final image 9have made a couple of processing attempts already). Tonight I will try and see if I can retake my flat frames and get something I can actually use. Hopefully that will save the image.

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