Bob Hughes wrote:
> 
> That's quite something there Spider, the blue perimeter box is markedly
> different from one image to the other. And I see other differences too,
> like the red shadow and it seems the yellow/magenta gradient doesn't
> convert to light and dark gray or it's just a visual perception thing.
Actually, it shouldn't be the exact dark, but I think it may be changed inside
the formula. This is the one I found, so this is the one I use.

> Have you done a grayscale image conversion to compare?
I did one, but anyone can do and see the difference, it doesn't change much, if
you want me to post it I will.

> Like the perfume bottle too, Johannes. Very fitting in B&W. I'm tempted
> to tease about the sky color being also the bottle color perhaps if a
> person didn't know about the color picture.
hehe

> I wanted to show a gamma related picture as well as the black and white.
> The b&w method is by way of hf_gray_16 output into a png. My
> Display_Gamma is always 2.2, except when doing the center image I
> removed it from Povray.ini and restarted POV to be sure it reset.
> Picture was originally 24-bit color png and image_mapped using only
> ambient 1 finish without any lights.
> Now my thoughts on it...
> The leftmost image is a washed out low-contrast mess. The middle one is
> what I would normally see if I don't adjust any gamma up or down. And
> the one at right is darker than I would usually ever do, except that in
> this instance I was trying for a high-contrast, glossy-photo look, while
> at the same time trying to show the better side of gamma correction,
> imho.
> The increased global ambient_light helped to brighten parts while the
> larger gamma number darkened it overall.
> Here's the lights used in the original image:
Yes, there is a difference beteween gamma, and the same difference is seen when
I convert my Greyscale in PSP5 to grayscale.. (now ain't that something...)
 

-- 
//Spider 
( spi### [at] bahnhofse ) [ http://www.bahnhof.se/~spider/ ]
#declare life = rand(seed(42))*sqrt(-1);

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