Globular cluster M2 is not quite as spectacular as its big brother, M13. Nevertheless, this kind of objects are always worth a picture!
For this image I kept exposures to 400 seconds, to prevent burning out the center of the cluster. I used clear luminance, together with R, G and B exposures.
Processing was not easy. I tried to sharpen the core and the external stars, using wavelets techniques. Several attempts were needed to get a balance between sharpening and softness. For this, a mask was used which protected the background and the stars.