"Slime" <fak### [at] emailaddress> wrote:
> > Very strange you don't see a problem.... I see a THICK BLUE circle around
> > the earth on the version I created with the "+UA" option.  When I tried
> > converting it to PPM format, the THICK BLUE circle was included.
>
> If you take the +UA version and put it on a black background in Photoshop,
> it's nearly identical to the original (some pixels around the edge are off
> by a very slight amount (7 or 8 out of 255), which might be caused by how
> POV-Ray handles transparency on emissive media).

Hmm... I have GIMP... perhaps you can show me how in GIMP?  (I don't have
Photoshop.)

> The majority of the visible
> difference is caused by the fact that you've displayed the second version on
> a grey background, which makes the blue ring around the earth more visible
> (probably mostly because of your monitor's gamma.)

Grey?  As in Grey and white checkerboard?  How do I change the background?
I didn't modify the source when I re-rendered using the "+UA" option.

And, yes, the atmosphere is very thick by design, so that I'll have plenty
of space to fade away the atmosphere without having any appearance of "hard
cut-off".

In this "game" I was playing, I was hoping to produce 2 identical images,
where 1 would have an alpha channel.  But I'm not convinced that I have 2
identical images.  Would like to see someone take the image with alpha,
remove the alpha and see if it looks identical to the first... and tell me
what software you used to do it (and I hope you mention "GIMP" :) )

Here's what I get when I attempt to remove the Alpha.  I get this using
XnView and NetPBM.  Obviously it's not identical to the original.  Maybe I
need more explanation?

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