What camera are you using? Was it the Moravian G4-9000 in your signature?
Thanks a lot for asking.
Last year I did this in 3500mm focal lenght with my 16" Meade ACF and Moravian G4-9000 mono with narrowband filters and with an Moravian G1 OAG:


The 16" Meade ACF+Moravian+10Micon GM HPS is a setup weighting more than 100Kg and would require 1-2 days to setup. I now suspect I can get better results with the same amount of time with an 11" RASA+ASI 6200MC+HAE69C-EC+ASKAR DUO+ filters and no guiding. The RASA would require 30 minutes of setup time including polar aligment. I can't move the 16 Meade to chase good seeing and even better darkness. I can do that with a 11" RASA. With high megapixels cameras you will want to crop the image if the target looks too small, that's it, as long as the limiting resolution of the telescope remains well below the seeing and enough pixels remain to properly sample target DSO.
I can't travel with my 16" Meade to Namibia, I can easily grab a 300mm f2.8 lens and my Sony A7III camera+ Staradventurer and go there.
Just for fun, last month I used my Skywatcher 100i+925 Edge HD and Sony A7III camera to take a total of 10 minutes of exposure time with sub 10second images of the Dumbbell Nebula while dodging clouds. This is a setup that many would qualify as crazzy, I wouldn't recommend an harmonic mount without encoders to be used unguided with this telescope. But because I was dodging clouds I decided not to guide. The results are not perfect but look more encouraging than what I though I would get at this long focal lenght.

Regarding planets, I'm still processing this picture of Saturn taken with my 20" f3.5 DocTelescope, unguided:

Dave I agree with you, a 11" Rasa is not a good planetary instrument, but I've never claimed that was the case. I would argue the 11" Edge HD is a more versatile instrument than the RASA because it can do planets and thanks to Hyperstar, it can also become a very fast telescope. But this isn't what we're discussing. What I'm talking about is that wether we like it or not, the sky is filling up with satellites and extraordinary dark sky places are long gone in Europe and the US, thankfully, fast telescopes/lenses and low noise CMOS tecnology are there to help.
Thanks to low noice CMOS, I'm also beginning to see very good narrowband results with 2" exposures too. I did not think this was possible, now I'm changing my mind.
To re-iterate, my current view is as follows:
When targeting DSOs of almost any size in OSC, get the fastest lens/telescope possible, don't guide, use short exposures with a good, low noise CMOS camera. This will eliminate layers of complexity and will enable imaging with even low end/low weight mounts. In the end you will get better SNR because you'll be trowing out less subs due to satellites, clouds and failed tracking and you will get a much more portable setup. This will encourage you to travel to better places to image and get better results. The only real tradeoff is slower computing times but let the CPU be misserable while you sleep, instead of loosing sleep while being miserable guiding away from home.
Of course, I don’t claim to possess the absolute truth here; these are simply my observations and preferences based on my experiences and current goals. I’m always open to constructive discussion and different perspectives, especially if they bring valuable insights. I welcome any feedback or suggestions that might add to the conversation.
Edited by PeterWar, 01 November 2024 - 10:35 AM.