Hi again, Roger,

Got your private message reply. Thanks for pointing me to my very early post from 2011. Here's the link to the message, which anyone can read:

http://forums.dc3.com/showthread.php...lign#post30373

I actually have never tried to use the "stack" directive, so I don't have any experience to pass along. For calibration, I typically set the "calibrate" checkbox in the ACP Preferences to automatically calibrate every image after taking it. For my small-FOV camera (10'x15' roughly) it's a very quick task to calibrate in real time. Other users may prefer to collect all the images first and then post-process them all at once later, during the day. For large-FOV cameras and in a scenario where high cadence rate or minimal interruption is sought, that's a very good idea as it doesn't slow down the cadence. So it all depends on what your needs are.

I have always used MaxIm after the fact to stack images - to produce color images from my filtered b/w camera images, for example, or to bring out more detail by combining images, or putting images together in a mosaic, or a "movie." When you use the #STACKALIGN directive, ACP will collect the appropriate images and then invoke MaxIm to actually do the stacking and aligning. Most of my research is on photometry of variable stars of many sorts, especially imaging at high time resolution. I might stare at one object for 11-12 hours (in this season), collecting 400 or so images. I don't want to stack them.

Regarding my response to Peter's question in 2011, I was just trying to clarify for him what was in the ACP Help file. These directives still exist. If you search on "stackalign" in the search bar at the top of this page, you'll see that there has been little problem with it, or perhaps hardly anyone uses the capability. One question a year, more or less. I suspect it's not a very frequently used tool.

I hope this helps you. Thanks again for getting in touch.