NGC 6910 (5-3-2011)

This lovely cluster illustrates the work I did on the telescope two days ago.  Previously, my stars were out of round, and I wasn't sure why.  I made three changes that day:  (1) I squared the focuser with the tube.  This is something I should have done earlier.  (2) I flocked the tube across from the focuser.  I was worried that light from the back of the secondary mirror was bouncing around inside the tube.  That will stop it.  (3) I blackened the back and sides of the secondary mirror with flat black paint.  I had an epiphany after I flocked the tube.  I looked down the eyepiece tube and saw ... the reflection off the side of the secondary, shining brightly right into the eyepiece.  I immediately knew the source of my out-of-round stars.  Time to get out the paint.  Now the stars are round.  They are beautiful.  The scope is doing what it's supposed to do now.

This picturesque cluster is just north of Sadr, or Gamma Cygni.  I was going to image something else, in the south, but my guiding was off because cables were catching on the mount.  Anyway, it was about 4 am, and I was too tired to diagnose the problem (I figured it out the next morning).  So, I thought, I'll try something near the zenith that I can actually catch in an hour.  An open cluster!  Sure.  Well, I caught the cluster, but this cluster is surrounded by nebulosity (of course, next to Sadr).  The time was too short to catch much of the nebulosity.  I guess an hour was too short.  I don't make my best decisions at 4 am.

Telescope: Orion 10" f/4.7 Newtonian
Camera & Exposure: SXVF-H9C, 13x5'
Coma Corrector: Baader RCC I
Filter: IDAS-LPS2
Guiding: Orion Deluxe OAG, Meade DSI Pro, PHD
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX

Here is a small gray-scale showing some of the nebulosity.