Rosette Nebula DSLR meet Ha


What I considered one of my best DSLR based astroimages was the Rosette Nebula. I had around 7 hours of data from a fairly dark sky location. I was pretty happy with my work, but I had always noticed the guys with CCD cameras were taking sharper pictures with smaller, more controlled stars. Since I now have a CCD like camera, I decided to reshoot this target. After gathering some data for a large mosaic project, I slewed over to shoot some Hydrogen alpha subs of the Rosette nebula. I decided to try both 90s and 120s subs. Normally I had been going for longer subs at a low gain setting, but new testing has shown this camera functions very well at high gain when properly calibrated. This allows for shorter subs. There is a trade-off here. The shorter subs tend to be sharper as changes in guiding/tracking are less of an issue, but the increased number of subs becomes difficult to handle. A few hours worth of data with 5 minute subs vs 90s subs is substantial.

It was immediately obvious how much more dynamic, sharp, and deep the Ha data was. I was thrilled that with less than two hours of data, the nebulous structure was so well defined. I combined the Ha with the DSLR’s RGB data and with minimal processing had an image I felt was leaps and bounds superior to my previous efforts. But it wasn’t quite what I wanted. Over the course of several days I reprocessed, tweaked and reprocessed again trying to get just the right balance of detail, low noise, and colors I wanted all while maintaining control of the stars.

I am pretty happy with how this turned out.


Full size here