This image is the enhanced core from an earlier post of the M5 star cluster (
http://www.astrobin.com/183829/C/). In the previous image the core was so bright that it is virtually impossible to represent it fairly along with the outer stars. This image is an attempt to correct that situation and show the M5 core as best the data is capable. In order to generate this M5 core image, all the subs were cropped and re-registered against a cropped luminescence reference image produced through drizzle integration. This generated a more tightly registered set of subs for the image. From that point, the processing proceeded in PixInsight and Photoshop.
The M5 core image has an insert showing the original posting. The core image is only 4.6 x 4.6 arcmin., versus the original image that was 30 x 20 arcmin. The core image is only about 5% of the original image area. There were approximately 450 x 450 pixels to work with in the original subs. With the drizzle integration that number was doubled. I took some additional liberties in Photoshop and increased the pixel value to around 2,000.
The stars in this image are certainly less defined than the original, having much fewer pixels to work with. However a lot more information shines through with the additional processing of the cropped subs and also setting the black point of the image near the edge. In addition, this is almost a linear image. That is, there was almost no stretching to produce the image you see. The core of M5 is very bright.
Enjoy.
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