Patrick wrote: <You are using a smaller chip than I am and your pixels are bigger and <yet your stars are sharply focused, tiny pinpoints as opposed to the <ugly splotches the stars form in my pictures. That is what Takahashi is all about! :) Seriously, the most likely reason for star bloat is poor tracking, but with your mount I don't think that is likely. It could also be focusing, but I assume you are getting your focus right (MaxIm is great for that). It is more likely to be a result of your processing. If you are lowering the white point to bring out detail in your image (which I suspect), then you will be causing your stars to bloat. You will also be causing portions of the image that once had detail to become washed out. Perhaps you could email one of your fits files to me so I could examine it. A dark subtracted version would be even better. I can easily tell if that is the issue leading to bigger stars. I would love to get together some night to take a pretty picture or two using your equipment. We could do a session of processing in Photoshop and MaxIm as well. <What is the effective focal length of your system? I'm running at about <1,800 mm. This image was taken with the Tak Epsilon 160 at F/3.3, for 528mm, so I am using a much shorter focal length than you. I also image with my Tak CN-212 at F/4 and F/10. My mount has trouble at F/10 and my stars show the tracking difficulties when I use it. <You note that your exposures are "Ha 10x1200s RGB 6x300s each". From <that I'm guessing you mean the Ha is a combination of ten 1,200 second <(20 minute) exposures and then you made an additional six 300 second (5 <minute) exposures for each of red, green and blue. <So that would be a total of 290 minutes or nearly 5 hours of exposures. < Have I got all that right? Yes, that is right. Lots of data makes for smoother images, so I collect as much as possible. <Also, for your 1,200 second luminance exposures did you also make 1,200 <second darks? <If so, did you make a series of 1,200 second darks and then combine them <into a master dark? If so, how many in the series? <How's about 300 second darks for the 300 second color exposures? More <than one and, if so, how many? I have a library of dark frames that I captured during the daytime when I couldn't image. I just make sure that the camera can cool to the temp I plan to use, and then start the camera taking darks. For the most part, I use 20 dark frames at each exposure length. I have created "Master Darks" for exposures of 1s, 5s, 10s, 20s, 30s, 60s, 120s, 180s, 300s, 600s, 900s, 1200s, and 1800s. It sounds like a lot of work, but I just use MaxIm to take a series of darks and let the camera work on its own all day. I also use bias frames (one Master for each resolution only), and I try to shoot a series of flats while I am imaging. I use a projector screen for that. <Would you be willing to email me one of those ten 1,200 second raw, <unprocessed FITS images you used to make your NGC 7380 picture? I'd <really like to see how your stars look before they've been dark <subtracted, flat fielded or PhotoShopped. I'll send one off ASAP. <Carpe Noctem! Same to you! Cheers, Tyler Tyler Allred President Allred Restoration, Inc. 670 W 1725 N Orem, UT 84057 801-358-1868 cell tylerallred@earthlink.net pw _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com