初十的直壁

C.L.Chan

農曆初九至十一是拍攝一道黑色的直壁的好日子.

Rupes Recta L=110km, w=2-3 km, h=240-300m.UT2020/10/26: 12h31m, Telescope TEC Maksutov-Cassegrain MC200/20,D=20cm, F.L.=400cm, Losmandy G-11 Equatorial Mount with motor drive. Camera QHY5III 224 Color Cam,  Shoot by FireCaptureat Gamma=100, Gain=38, Expo= 0.3ms/frame, frame rate=20 frames/sec, RGB &avi format, stack and process 25% best frames in 1803 frames,­ with SoftwareAstroStackert 3 with DSR, wavelet with RegiStax V.6,  final touch by Microsoft photo. Atmosphericcondition: Transparent: 9­/10, Seeing: 6/10, Equipment borrowed from Mr. Ng.The photo was taken at Kennedy Town堅尼地城, Hong Kong.