Re: [APML] NGC7822, Ced214, and Sh2-170

["tan@home.com" <tan@home.com>]

Chuck,

	I try to keep them the same but sometimes dawn is approaching and I run 
out of time <g>. Also sometimes I have noticed that using the 
predetermined exposure ratios does not get me to the sky fog limit for 
each color. I have noticed that red reaches the sky fog limit before the 
others do and as such either my exposure ratios are incorrect or blue 
and green is suffering from reciprocity for longer exposures. I guess 
one question I have about correct exposure ratios are, should all 3 RGB 
channels achieve the sky fog limit at the same time if the exposure 
ratios are correct and if I exposed for a suffciently long time. I would 
think this should be the case but it is not what I am seeing in practice.
	As such, I would rather the blue and green achieve the sky fog limit and 
have more detail rather than be color correct. At least for color, I 
could compensate for this somewhat in Photoshop whereas if I 
underexposed, I would never get back what I've lost in detail. Bottom 
line is, I am willing to sacrifice color correctness for a deeper 
exposure. I would be interested in your experience with this. Thanks.

Loke


Chuck Vaughn wrote:

> Loke,
> 
> Why are you using different ratios of RBG exposure times on different
> images? The color balance will be different in every image.
> 
> Chuck <aa6g@aa6g.org>
> 
> ------------------------
> 
> 
>>Hi,
>>
>>Here is a shot of NGC7822, Ced214 in Cepheus, and Sh2-170 in Cassiopeia
>>taken last new moon with the 8" f/1.5 Schmidt camera using the tricolor
>>techique. Exposure details are on the webpage. This is my 3rd attempt of
>>this object. The first time, Sh2-170 was framed incorrectly while the
>>2nd attempt, my location had a tremendous amount of moisture which
>>caused a bunch of blotches to appear on the negatives. The 3rd and final
>>attempt turned out better than the first two. Comments are welcomed.
>>
>>http://www.starryscapes.com/nebula/ngc7822.html
>>
>>Loke
>>
> 
> 
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