> Op 12/11/2019 om 17:04 schreef Alain Martel:


>>>
>>
>> It's similar to a gradient y, but with only a single ramp.
>> function {max (min (y, 1), 0)}
>>
>> The max(y,0) clamp out everything under 0.
>> The min(y,1) clamp out everything over 1.
>> Leaving you with :
>> -infinity..0 =0, [0..1] ramping from zero to one, than stay at one.
>> It is extremely bright, ranging from White*2.35 up to White*13.5.
>> It may be intended to simulate the glare from the Sun at the zenith.
>>
> 
> I assumed as much but personally I am very wary of rgb values higher 
> than 1, and these are really extreme. In such cases I much prefer to use 
> a finish {emission} setting instead.
> 
Then again, with assumed_gamma set to 2.2, those get's compressed quite 
a lot.

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> Op 12/11/2019 om 17:04 schreef Alain Martel:


>>>
>>
>> It's similar to a gradient y, but with only a single ramp.
>> function {max (min (y, 1), 0)}
>>
>> The max(y,0) clamp out everything under 0.
>> The min(y,1) clamp out everything over 1.
>> Leaving you with :
>> -infinity..0 =0, [0..1] ramping from zero to one, than stay at one.
>> It is extremely bright, ranging from White*2.35 up to White*13.5.
>> It may be intended to simulate the glare from the Sun at the zenith.
>>
> 
> I assumed as much but personally I am very wary of rgb values higher 
> than 1, and these are really extreme. In such cases I much prefer to use 
> a finish {emission} setting instead.
> 

You may try using srgb instead of rgb when declaring the colours.

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Op 14/11/2019 om 03:11 schreef Alain Martel:

>> Op 12/11/2019 om 17:04 schreef Alain Martel:


>>>>
>>>
>>> It's similar to a gradient y, but with only a single ramp.
>>> function {max (min (y, 1), 0)}
>>>
>>> The max(y,0) clamp out everything under 0.
>>> The min(y,1) clamp out everything over 1.
>>> Leaving you with :
>>> -infinity..0 =0, [0..1] ramping from zero to one, than stay at one.
>>> It is extremely bright, ranging from White*2.35 up to White*13.5.
>>> It may be intended to simulate the glare from the Sun at the zenith.
>>>
>>
>> I assumed as much but personally I am very wary of rgb values higher 
>> than 1, and these are really extreme. In such cases I much prefer to 
>> use a finish {emission} setting instead.
>>
> 
> You may try using srgb instead of rgb when declaring the colours.

I did initially but I was not satisfied with the results at all. Then I 
started messing around. I may go back to srgb again...

-- 
Thomas

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Here, my latest (and last for now) experiment with going from 
assumed_gamma 2.2 to assumed_gamma 1.0.

I used the adapted colour_map for the sky_sphere proposed by Alain 
Martel, and I changed all colours to srgb. Tweaked the light intensity 
and the colour_map intensity a bit to get what I think is a clean and 
correct image.

I also append a copy of my latest scene file with changes.

-- 
Thomas

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Attachments:
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Preview of image 'nk_assumed gamma discussion_5.png'

> Here, my latest (and last for now) experiment with going from 
> assumed_gamma 2.2 to assumed_gamma 1.0.
> 
> I used the adapted colour_map for the sky_sphere proposed by Alain 
> Martel, and I changed all colours to srgb. Tweaked the light intensity 
> and the colour_map intensity a bit to get what I think is a clean and 
> correct image.
> 
> I also append a copy of my latest scene file with changes.
> 

Definite improvement.

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Hello,

thank you all for the input.
Because of real life interferences I wasn't able to answer in due time in the
last weeks. I hope it's getting better.

Regarding William F Pokorny - I normally render my images with 8000*4500 or even
16000*9000 pixels (like in this case) and scale down via photoshop. I simply
like the details in big renders and the smooth crispy look of the scaled down
versions.

Norbert

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