Finally a clear night for the first test of my IR modded, cold-finger cooled 450D. It was not really a cooling test as as the ambient temperature dropped down to 1C and the cooler hardly did anything.
The moon was high in the sky so I decided to try out my H alpha filter for the first time. This filter is not an astronomical filter. I am guessing that the transmission is about 50% and the bandwidth may be as narrow as 1nm FWHM. Not sure. The focusing was a real pain as live view was not registering anything. I had to take 30s exposures of a bright star and look for change in star size while adjusting the focus.
The filter was held by sticky tape on the top of my field flattener
DSLR was not debayered and only every 4th pixel on the sensor was used. I used dcraw to convert the RAW files to TIF and then octave to extract the red channel only.
- 29 x 3min lights (1h 27min total)
- bias used instead of darks
- no flats (got too excited and forgot to do them)
- Stacked with DSS, processed with StarTools