For base colour, What do tolerate range and stricker range mean?

[HapZungLam]

From the PBR guide 2.  It says "The range for Dark Values could be more tolerant at 30sRGB and stricker at 50sRGB" 

From DONTNOD Physically based rendering chart for Unreal Engine 4 (the link included from the guide) suggest "The diffuse part of the base color (the one use by the non-metallic) must be in the range of the first gradient 50-243."

What do tolerate range and stricker range mean?

Are dark value don't go under 30 and 50 a general rule of PBR or its just for UE4.

[Wes McDermott]

From the PBR guide 2.  It says "The range for Dark Values could be more tolerant at 30sRGB and stricker at 50sRGB" 

From DONTNOD Physically based rendering chart for Unreal Engine 4 (the link included from the guide) suggest "The diffuse part of the base color (the one use by the non-metallic) must be in the range of the first gradient 50-243."

What do tolerate range and stricker range mean?

Are dark value don't go under 30 and 50 a general rule of PBR or its just for UE4.

Hi,

As a general rule you don't want a dark value to go below 30 sRGB. A more strict range is to say don't go below 50 sRGB. This is a general guide for all PBR and not just UE4.

Cheers,
Wes