Visibility IV / V
Shooting a gauze fog with a modified camera had been in my plans for some time. In particular, I have been interested to see how much red light accumulates from the fog, which, especially among visual observers, is accustomed to feel most visible in the light of the O-III spectral line, but in photographs usually anything but monochrome green.
Most of the exposures I took of the subject were half a minute long. The eastern part of the object, which stands out on the left (NGC 6992), was, as expected, brighter than the western side visible near the right edge of the image (NGC 6960). The so-called Pickering triangle stands out between them closer to the west. The dimmer parts of the fog complex that fit in the image area are between NGC 6974 and NGC 6979 between the Pickering triangle and the eastern part. Immediately to the west of Harsosumu is a dark mist that appears as a slightly darker area relative to the rest of the star field in the image.
I took my picture during the Altair observation night, and while filming we were already watching the clearly dimmed Jacques comet with a telescope. Unfortunately, however, the comet was on top of a brighter star at the same time, and the fogging of the optics didn’t particularly help Koma stand out. However, I have to look at the comet again.