Date: 1/15/2011
Location: Sam Bruno, CA
Instrument: Orion Mak Cassegrain with Imaging Source DMK camera at f/d 15
Infrared Filter Astronomik IR Pro 742
Processing: Avistack for Image stacking, Astraimage Wavelet processing, Photoshop CS4
Seeing: 3-4/10
The use of the Infrared pass filter (pass wavelength above 742nm) allowed to pass through the turbulence. Not only the image was much more stable but showed also improved contrast (compared to a regular Infrared Cut filter).
Even if the IR pass filter reduces luminosity, the moon is such a bright object that each frame integration time is still small (1/10 second by frame for this picture – about 1,000 stacked frames ).
Astrophotography in Urban Environment 