Richard, It is not just the software. eXcalibrator finds all of the G2V stars in an image (which are the same class of stars as our Sun), which we see as white. If your color balance is right, all of these stars should look white in the image. I use the color factors that will make these stars look white, hence the color balance should be "right". I know there can be variances depending on filters and atmospheric refraction, but the difference should not be that much. Thanks, Bernard -----Original Message----- From: az-observing-bounce@xxxxxxxxxxxxx [mailto:az-observing-bounce@xxxxxxxxxxxxx] On Behalf Of Richard Harshaw Sent: Monday, May 20, 2013 10:12 PM To: az-observing@xxxxxxxxxxxxx Subject: [AZ-Observing] Re: NGC3718 an d NGC3729 Great image. As for color, software says it is the right color based on the instructions written by the programmer. And where did the programmer get THEIR decision process? Ah, who knows... Richard Harshaw Cave Creek, Arizona Brilliant Sky Observatory -----Original Message----- From: az-observing-bounce@xxxxxxxxxxxxx [mailto:az-observing-bounce@xxxxxxxxxxxxx] On Behalf Of Bernard Miller Sent: Monday, May 20, 2013 7:51 PM To: az-observing@xxxxxxxxxxxxx Subject: [AZ-Observing] NGC3718 an d NGC3729 Hi, Here is an image of NGC3718 and its companion NGC3729. These two galaxies orbit each other with a separation of about 147,000 light years. These two galaxies are in Ursa Major. It seems most of the images on the web show this galaxy as blue, but Excalibrator says this is the right color. I am not sure why the other images are blue. Comments and suggestions are welcomed. http://www.azstarman.net/NGC3718.htm Bernard -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list. -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list. -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.