Andromeda Galaxy M31 in LRGB with HyperStar Lens 10-29-16

I'm still trying to get a handle with using the Hyperstar lens at f/2. This shot of the Andromeda Galaxy M31 is my second LRGB effort with the HyperStar. I believe that my exposures are still too long. I probably could have cut the exposure time in half, and not blown out the core region. I did manage to capture some nice dust lane detail. Also have a nice view of smaller galaxies M110 and M32. Used my Celestron EdgeHD 11 in HyperStar mode, on top of a Atlas AZ-EQ/G mount. Focal length 560mm at f/2/. Guiding was accomplished using an Orion StarShoot mini-guider (SSAG). Capturing camera was a Atik 460ex, with Astrodon LRGB filters. Captured 15x300sec L,R,G and B Lights. No Flats, Darks or Bias frames applied. I do have some vignetting and will need to definitely do Flats to address that issue. Processed with PixInsight and Photoshop CS6. I'll keep plugging away until I get it right.