Le 2025-09-11 à 10:27, Cousin Ricky a écrit :
> On 2025-09-11 03:24 (-4), William F Pokorny wrote:
>> On 9/10/25 20:08, Cousin Ricky wrote:
>>> I tried samples 10, 10, and that improved the reflection; but now the
>>> media photons are considerably dimmer than before.
>>
>> [snip]
>>
>> A simple example. Suppose looking down on the media box we have,
>> vertically, a very thin layer of deposited photons. In our set up we
>> take 3 primary samples and no adaptive samples. Further, camera ray
>> paths traveling down into the media box are such that only the middle
>> sample of the 3 lands in the middle of our thin layer of deposited media
>> photons. The resultant media intensity is calculated as 1/3 for the
>> three samples.
>>
>> Now we up the samples to 10, but still only one of those 10 sample lands
>> in our thin layer of deposited photons. The calculated media intensity
>> is now 1/10 for the samples taken.
>>
>> [snip]
>>
>> With that mirror's reflected rays, and our simple example, we could have
>> reflected ray paths which run much 'longer' within that thin layer of
>> deposited photons than they do more generally in the scene - resulting
>> in unrealistically bright reflections.
> 
> So, what I'm getting is that my earlier renders were too bright, and the
> "dimming" is actually a correction.  I had set my media box much wider
> than the light beam because I wanted to catch any light that got
> refracted outside reflection layer.  Looks like I'll have to customize
> my media container if I want to catch those refracted rays without
> blowing up the render time.
> 

Alternate of doing it without any media :

Have a back plane with a white pigment and a finish with «brilliance 0»

Next : Have the beam slant slightly down.

brilliance 0 cause the illumination to be independent from the incident 
angle.

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