The Cocoon Nebula

This image was actually taken on 8/18/12.  I have been working on this image a few times, and although previous attempts were not bad, I have been struggling with amp glow with the Canon 300D.

Today, I took 25 bias frames.  These are similar to dark frames - the lens cover is on, and the shutter speed set to 1/4000 second.  The idea is to measure the pixel bias and subtract that bias from the flats, darks and lights.  When I used the bias frames, the amplifier glow vanished!  This made the image much easier to process and got rid of some nasty gradients on the right side of the image.  I will have to try this out on the 1100D also, as I have some really bad gradients on it that I havent been able to process out.  This might be the missing link.  Although it did not remove ALL of the amp glow, it did remove most of it.

Here is the final image of the Cocoon Nebula (IC 5146, Caldwell 19).

The Cocoon Nebula lies at the end of Barnard 168, a dark nebula, which is visible in this image as the area above the red Cocoon that is mostly absent of stars.  If you also look closely, there is some dim blueish nebulocity on the edge of the red, on the bottom right part of the Cocoon in this image.  Although not as prominent in the Cocoon as in the Trifid, all 3 types of nebulocity exist in this object.