Last year I imaged this object using a DSLR so haven’t learnt my lesson about trying to image the dim magnitude 9 Rosette Nebula with a DSLR during a warm summer night with average seeing
My Canon 600D was reading 33 deg C on BYEOS
A few test frames looked ok so took about 40 x 3 minute subs and 25 x darks
Dithered each sub and guiding was sub arc second
FOV using my 8” f5 newt and Canon APS-C sensor could only fit about 65% of the whole Nebula too
After stacking in DSS and stretching in Startools , the noise was atrocious and medium to larger stars were bloated
Tried to minimise the noise using many modules and noise reduction but the end result was poor
I’m not going to waist my time on this object anymore unless I have a cooled OSC Camera. If this object was hypothetically around during mid winter , outside air 10deg C and DSLR running at around 17 degrees, the final outcome would be a lot different and worth throwing some late nights into it
I used to feel the same way about my unmodded DSLR. Currently I'm reprocessing my LMC capture from last year and while it's not an object as dim as the Rosette, I too am having similar issues to you. Noise from a hot sensor and washed out subs with crazy gradients from LP. However, now I just see it as a developmental challenge which hopefully will improve my processing workflow. There's no doubt that a cooled camera will produce better results, but you've done pretty well here to get where you have with what you have.
I know how you feel Martin but your result is pretty nice and it's good to show beginners what they may be up against using this type of equipment under warm climatic conditions. Despite your disappointment, it was a good idea to share your image.
I set a very high bar for myself but keep forgetting a DSLR has its limitations, great results in the cooler months but too noisy in the warmer months
I plan to jump ship later this year to a ZWO cooled OSC camera using APT but still use the DSLR as well
