In the world with very fast systems, this is going to be pretty common. Even still, most who use those systems will want more time, if available.
Here are a few sub 1hr shots I got have posted:
M 42 The Great Orion Nebula in OSCA whole 20 minutes on this one. For me, a rare night in winter, and this only fits between a couple big trees, so I have never been back to get more data. On the other hand, I am not complaining either... It could be said that high surface brightness is the key for this one. However, that does not really explain the decent dark clouds I was able to get. This was very early on in my astrophotography journey, so I might revisit this in reprocessing to see what improvements could be had.
NGC 2237I was able to go all out on this at 50 minutes. This is the first thing I ever posted on Astrobin. I would certainly love to get more data on this. Also, better current processing by me would certainly, likely improve things here.
IC 405 Flaming Star28 minutes for this one. Another very early image in my career doing this stuff, so there is much to be improved with my current processing skills. This one I got back too more recently with new data. Its hard to say that nice images cannot be achieved in a short period of time for a good number of objects. It helps if one is not inclined to pixel peep.
Back to the very fast systems, such as the RASAs, while these may be extreme examples, I honestly find with my 11 inch and a OSC camera, I cannot justify spending much more than 3 hr on
any object. Yes, when reading older literature (not that old!), it is always said that more data means a better, deeper image. But I believe that after a certain amount of time, the gains become so diminished that it is pointless. I have limited means to display my work. This includes printing (usually on metal) and on computer screens of various forms. With a widefield telescope, I generally frame the work for best viewing scale to meet these requirements. All have their limits. And none are like putting an image up on a IMAX screen! So, given that I live in a location that is mostly cloudy, or otherwise unfavorable most of the year, I do not waste my time using 2, 3 or 4X the exposure times to give me a percent improvement in the image. I am sure other imaging rigs are more prone to improvements with more exposure time, but for the fast systems, really, sky background ends up being the limiting boundary for any gains if one is trying to meet the limits of detection for deep sky stuff.
