Hi,

While playing with Photons and dispersion I noticed that higher 
dispersion_samples also gives brighter refractive photons.
With dispersion_samples 7 (default) the brightness is equal to photons 
without dispersion, but with for example 14, they are way too bright.

I guess the brightness of each color-band is divided through the default 
dispersion_samples of 7 instead the dispersion_samples actually used in 
the texture.

Win98SE, Pov 3.5 beta 6

Lutz-Peter

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Here is a scene to demonstate the bug:

#version 3.5; // beta 6

global_settings
{       
	assumed_gamma 2
	photons{count 5000}
}

camera{location <1,4,-4> look_at <.5,0,0> angle 60}

light_source{<-10,4,0>	color rgb 1}

plane{y,0 pigment{color rgb 1}}

prism
{
	0,1,3,<-.5,.001>,<.5,.001>,<.001,1> rotate -x*90
	
	pigment{color rgbt <1,1,1,.8>}
	
	interior
	{
		ior 1.2
		dispersion 1.05
		dispersion_samples 7 // higher-> brighter!
	}
	
	photons
	{
		target
		refraction on
		collect off
	} 
}

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Lutz-Peter Hooge wrote:
> 
> While playing with Photons and dispersion I noticed that higher
> dispersion_samples also gives brighter refractive photons.
> With dispersion_samples 7 (default) the brightness is equal to photons
> without dispersion, but with for example 14, they are way too bright.
>
> Win98SE, Pov 3.5 beta 6

Same with beta 7 both compiles. This is not on the known bugs list.
I used a different scene with dispersion samples 100:
http://lightning.prohosting.com/~lf/dispersion2.jpg

_____________
Kari Kivisalo

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