RE: [APML] question on HorseHead shot

["Jon Kolb" <jkolb@datawest.net>]

Hi Bobby,

> This shot is pretty deep and the question I have concerns the 
> nebulosity on the right side of the image. I don't see this 
> on most shots of this region, but there are hints of it on 
> one of my images. Is this nebulosity really here or has it 
> been overly enhanced (even created?) from differential 
> reciprocity failure of the green and blue layers of the E200 
> out at the edge of the frame caused by light fall-off and 
> vignetting? I often get some of this at the edged of the 
> frames and usually process it out, but it gets down to 
> judgement on how much red is really there sometimes. Does 
> anyone know of a deep shot of this region I can check? Bobby Middleton

The whole region between the Horsehead and M42, and even in between
these objects and Barnard's loop, is filled with nebulosity.  Take a
look at a larger view: http://home.datawest.net/jkolb/central_orion.htm.
I think the nebulosity in your shot is definitely real.

Sincerely,
Jon Kolb
Adventures in Astrophotography
http://home.datawest.net/jkolb/
jkolb@datawest.net




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