I can reprdouce the noisy torus here in all versions of pov under linux 
(official, megapov...). POV sometimes shows unexpected results when you use 
very large or very small numbers. Unfortunately large means already  around 
10000 in some cases. If you scale your whole scene by a factor 1/100 then 
the noise disappears. 

There are some magic constants in the pov source code which control that; 
so I could reduce an other such misbehavior (showing up with very small 
numbers and blobs) by changing one of the constants. Therefore it seems to 
me that some of these contants are chosen quite arbitrarly. (This might be 
a thread for p.programming to discuss about).

As I said scaling everything makes the noise disappear
e.g:

> 
> #include "colors.inc"
> 
> camera  {
>    location <-5000,-25000,-40000>
>    look_at <300,-1300,-1500>
>    angle 1
> //   location <-500,-2500,-4000>
> //   look_at <300,-1300,-1500>
> //   angle 10

scale .01  

> }
> 

union{

> light_source {
>   <-5000,-16000,-30000>
>   color White
> }
> 
> torus  {
>    66,33 sturm
>    rotate x*90
>    translate <-66,116,0>
>    rotate z*90 rotate y*180 translate <175.5,-970,-1027>
>    pigment {White}
> }

scale .01
}

will show the correct rendering.

- micha

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