Process lights only?

Of course, just don't add calibration frames. I often only do lights. With a good sensor, good optics, you can often get by without calibration.

Like @astrogee says, yes totally possible. For a really nice result you would need a near perfect sensor for not using any calibration though, even the most expensive ones do have some amp-glow and such. And you'd need perfect illumination as well without any dust to get away from flats. It's possible, but usually very expensive. And I think using bias will enable you to stretch more.

@vincent-mod  Thanks for your replies.  Some nights at the end of a session, I want to take a quick look at a target, but not do a full blown session.  Just take a handful of lights and process those.  Did not know if APP would do that or not.  I just got the trial last night.

Posted by: @vincent-mod

Like @astrogee says, yes totally possible. For a really nice result you would need a near perfect sensor for not using any calibration though, even the most expensive ones do have some amp-glow and such. And you'd need perfect illumination as well without any dust to get away from flats. It's possible, but usually very expensive. And I think using bias will enable you to stretch more.

I used a modded Pentax K-5II to start, and didn't really know what amp glow was that people were referring to. No bias issues either. Then I bought an ASI294 Pro-cooled - talk about amp glow! Now I have to do darks for sure. The Pentax K-5II sensor (by Sony) is probably one of the best. ZWO now puts it in the ASI071 - $2000 astrocam. I loved it but I could not control the Pentax so I gave it up for an astrocam 😢