Just the stars. This is my first open cluster and it is an interesting processing challenge. How do you keep color in all of the stars? How much color? What should the background level be? Should you deconvolve? My answers so far:

- Reduce the sub exposure time to 120 seconds. This allowed only a handful of stars to saturate

- Use ArcSinh stretch to keep the star colors intact

- Use the dark nebula sections to set the black point and let the areas around the cluster look like it is being lit by stars (it is!)

- Yes deconvolve to tighten the stars and help them look like the points they are

I didn't have a 120 second dark handy so I did what you are not supposed to do and scaled a 300 second dark with a CMOS camera. It worked quite well. But then I wasn't stretching hard to reveal dim nebulosity either.

One very big learning was with Cosmetic Correction. I routinely use CC due to the imperfect dark calibration with the QHY600M (scaled or not). I tend to use both the dark frame correction and auto-correction with sigma values of 3.0-5.0. However, the Auto cold pixel correction produced white lines between two nearby bright stars. This happened even with very light application of the auto cold pixel correction. Henceforth I will stick to dark frame correction only and let the rest be rejected.

Deconvolution was done with CCDStack. PI's deconvolution is great but requires so much trial and error that I usually just use CCDStack. Decon is always just a single button push for me there.

To resolve the hard edges on the 4-5 saturated stars, I did a small selection on their core and then a really small gaussian blur - something like 0.4 pixels. Sometimes I will follow that blur with a slight unsharp masking to re-brighten the core.

Noise reduction was done with Adobe camera raw and masked to affect only the background. No need for noise reduction on stars and so a simple noise reduction method got the job done.

I always look at the first subs and ask myself "what is the picture about"? For me this one was about the young blue stars, almost a globular, sitting on top of the older, redder star field. Not a stunner, but nice for a change.