M20, the Trifid, is certainly one of the most common objects to capture. I've been in this hobby for 17 years now and in all that time I've only tried to capture M20 once, back in 2009 (you'll laugh when you see that one!). Unfortunately from my home it is very low and blocked by some trees for a good part of the night. Yet I have always wanted to capture this little gem again.
The opportunity came while my family and I were traveling this summer in an RV, visiting many dark sites and national parks. This image came on the last clear night I had on the whole trip, July 4 near Natural Bridges National Monument in south central Utah. The sky here was perhaps the darkest I will ever see (I hope not!). It registered 21.89 sqm.
The image of M20 consists of just over 4 hours of total exposure, FAR less than I typically get, yet there was hardly any noise to deal with. Normally I have two scopes on a tandem setup capturing data. My CFF135 + G3-16200M generally captures LUM data while my SV80ST + QHY163M captures RGB. In this case, I had the 16200 capture LUM and 4x10min of RGB each and I'm really glad I did that because my QHY163 data was basically unusable. I didn't discover this until I started to process the data, but for some reason the QHY163 filter wheel didn't rotate the whole night, so the QHY163 also captured LUM data all night long. Believe it or not, all that QHY LUM data didn't really add anything to the LUM data of the 16200, so I just left it out. So, I had only 2hrs of LUM data and 40min each of RGB data.
Despite all that I'm quite pleased with how the image turned out. Dark skies REALLY helps!