I spent most of these 4 moonless nights with dark sky (around 21.3 SQM) to image this nebula with LRGB filters.

17 hours is currently my longest total exposure on a single target. Stars with mag 22.5 should be visible (with SNR=5) on the image.

My AO was off, and I use multistar guiding with PHD2 directly on the CEM120EC2 mount. It worked well but apparently, I was better not using to fast corrections (it seems to interfere with the encoders work). I used typically 2 sec guide steps. My objective is to use back AO with faster guide steps.

The image is color balanced on stars.

The processing was done in PI as follow :
For each L, R, G, B channels :
- Images Calibration (Dark Substraction, deFlat)
- Cosmetic Correction
- Image Registration
- Image Integration
- Mure Denoise
Then :
- Create super L image (integration of L and RGB individual channel)
- Create RGB image and color balance using R,G,B channels
- LRGB combination with superL
- DBE
- Color balance on stars
- Color Saturation masked (and desaturate bkg)
- Deconvolution masked with 1.8 pixel psf
- Background extraction
- Going NL using HT
- TGV denoise (no mask)
- Local Histogram Equalisation (at 90 pix scale)
- Color Saturation masked using stars to boost stars color
- Color Balance on stars
- Color Saturation masked using stars to boost stars color
- Deflip
- Crop

Final image adjustments performed in Iphoto on Imac :
- levels adjustments