5x30 sec + 5x150 sec as an HDR stack. Is it just me? or is there really a thin veil of cloudiness surrounding them? I think it really is there, but every time I attempt this pair, the terrestrial clouds roll in. Caught this one just in time. At any rate, I almost have the collimation licked.
The revised image shows an exaggeration of what PixInsight believes is in that HDR data... maybe? Add a bit more dark-lane enhancement, and neutralize the greenish tint a bit. The dark lanes actually start to look like what they probably really are - dark clouds of dust and gas overlaying the region, not gaps in the star distribution.
(Chrominance, anyone? What color is black, anyway? Ionized Hydrogen? Looks like I should take shorter exposures next time.)
Well, maybe so, according to Fabian:
http://apod.nasa.gov/apod/ap140123.htmlSo I would have to question whether I am just stretching noise, or actually detecting real background. Fabian makes my stretching seem plausible. I guess the only real answer will come from a more prolonged study, longer exposures. Fabian was using a 7 nm narrow H-alpha filter to get his nebulosity. I am using a relative broadband R channel through a LP filter. Plus I have F/2 and he was at F/4.5.
That means I need about 6 times less exposure than him to get the same pixel density, just due to F-ratio, even if using the same narrowband filter. His was 3 hours. I should need about 30 minutes. These images represent about 15 minutes through a broader filter, and I have much lower pixel density. So things appear to be in line, and I may not just be stretching noise.
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