Hi I have a problem with my new setup : Takahashy FSQ 106 EDX4 with SBIG1102 STXL with integrated fw8 and ASTRONOMIK filters In RGB composition the images (specially in nebulas) take on a color that is always turned into magenta as if there was an excess of blue filter !!! Very Bad Could it depend on the set of ASTRONOMIK filter used ? Replacing the filters with BAADER would solve the problem ? It may depend on the CCD instead ? This is the result ....
It depends on your calibration process. You need to start by figuring out what WHITE looks like. For example: - calibrate on a G2V star, - or point your camera at an 18% grey card/white card illuminated at 5000K (natural daylight). - find out the relative transmission at the band pass of each filter and the QE of the sensor at those wavelengths, and calculate the % to cut/boost the exposure time or the combine color values. The KAI-11002 has QE like this: (Chart courtesy of ON Semiconductor - KAI-11002 data sheet) Blue 440nm 0.46 Green 510nm 0.50 Red 700nm 0.24 So, for this chip, your red data needs to be 0.5/0.24 = 2.08 x as much as green data. Then factor in the filter transmission (if they allow different amounts of light through at their wavelengths - get that data from Astronomik).
