Here is a recent photo of M31 taken through my new STXL16200 and a Tele-Vue NP101-is. I noticed when I did the LRGB combine that I had to weight the blue quite a lot (1.25X) to avoid getting a really yellow image. Is this typical for the STXL16200 ? The stack is 4X600 sec L and 3 X 600 Sec each for R, G, and B. There is some slight elongation of the stars in the corners. Do you think that the large field corrector that TeleVue offers for the NP101-is will eliminate that ?