NGC 6992 September 2003

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Subject	NGC 6992
Date	September 2003
Telescope or Lens	Vixen ED102SS
Mount	G11
Camera	SXV H9
Filters	TT RGB, Schuler 10nm Ha
Total Exposures	L	6 hours	R	3 hours	G	3 hours	B	3 hours
Sub exposure	6 frames. Each 2 x 30 min		6 frames. Each 1 x 30 min		6 frames. Each 1 x 30 min		6 frames. Each 1 x 30 min
Binning	Luminance 1x1 RGB 2x2
Field of view and resolution	Approx 1.2 x 1.4 Degrees. 2 Arcsec / Pixel

Comments

This is my first attempt at a colour mosaic. The layout is 2 frames wide by 3 deep. It presented some challenges, particularly in balancing the colours across the frames. The hardest part was trying to get the green gradient from light polution removed from different places in the frames. I tried to take the colour shots at roughly the same altitude and position relative to the local lighting to minimise the differences but even this did not produce even illumination. Slight differences in the sky transparency makes all the difference and it was not possible to take all of one colour in one session. Some cropping of the image was needed so I have not made maximum use of the available chip size. This was unfortunate but to be expected to some degree as I have to set up my equipment for each session so I suffered from some camera rotation and needed more overlap. Not perfect but I think a reasonable first effort.