QHY247C - using one of those new duo-narrowband filters. The image noise is exceedingly low and if we start seeing mono CMOS APS-C cameras, it will kill off the KAF8300
I forgot to say, this was using 20-min exposures. What tiny amount of amp glow came up was taken out by the calibration. You have to remember to calibrate differently, as Alessio Beltrame pointed out, only using darks and flats to calibrate lights, and avoiding any dark-bias operations or dark scaling.