Re: [APML] Histograms, curving and layers

[Matt BenDaniel <matt@starmatt.com>]

At 16:16 04-12-02 -0800, Alan Voetsch wrote:
>I finally got around to reading Matt's article on
>'Curving Your Astrophotos'. I'd like to congratulate
>Matt on an informative, well written article. 

Thanks. I'm always looking for suggestions for more articles.

>I'm
>either getting smarter, or the article is written with
>little jargon and tech-talk. Probably the latter. :-)
>
>The text explained one area that has continually
>confused me; that was whether to curve individual
>channels, or to curve the composite. 

I spend most of my curving effort on the individual color channels.

>I also now know
>what a histogram needs to look like and that the left
>side represents black and the right, white. Thanks
>Matt, you may have accomplished the impossible:
>getttng me to begin understanding what goes on in PS.
>
>Under 'Anti-vignetting' Matt states that the AV layer
>should be under the curve layer. Why? Is a processed
>image really just an assemblage of processing layers
>as opposed to a single integrated image? 

The order matters a lot. If one layer clips the image, nothing above it in the layer stack will rescue the lost info. I find that an AV layer works best if it is right above the source layer. When doing AV, I'll alternate adjustments to the AV layer and to the main curves layer. Their adjustment is intertwined.

>Would it
>change the appearance much if the layers were
>reversed?
>
>Thanks,
>Alan

--
Matt BenDaniel
matt@starmatt.com
http://starmatt.com


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