This is data from 10th November 2010 and this time I have used all the 54 sub-exposures (4-minutes per sub) by treating the raw data slightly differently. If I simply colour convert the 16-bit FITS files, then some come out as if there was cloud (or fogging of the CCD). If however I first convert to IEEE floating point format and then do the colour conversion – the problem goes away – not sure why – don’t care why – it allows me to use all the data and that’s all I care about.
I have shown this one before a while back. I looked at my star map to find two differently coloured (bright) stars that were also pretty close together so that I could get both in the FOV of the Sky 90/M25C. Having done Albireo a long while ago, I found this beautiful star-pair Algol (beta Persei) and Rho Persei in Perseus. Processing by yours truly 🙂