Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: cjwidd on 2019-04-11, 01:15:27

Title: [RESOLVED] Corona Color vs. Output
Post by: cjwidd on 2019-04-11, 01:15:27

After conducting a few tests it is clear that, at least for the bitmap tested, an output RGB level of 8.0 is equivalent to a Corona Color Correct Exposure value of 3.0.

Could someone explain the equivalence mapping between these two modifiers?

Title: Re: Corona Color vs. Output
Post by: Njen on 2019-04-11, 03:17:04

That math is correct. Exposure is logarithmic, and multiplier is linear, so an exposure of three is 2 to the power of 3, which is 8:

2 * 2 * 2 = 8

To be more clear, if your original value is 1, then:
+0 exposure  = a value of 1
+1 exposure = a value of 2
+2 exposure = a value of 4
+3 exposure = a value of 8
+4 exposure = a value of 16
etc.

It also works the other way too:
-1 exposure = 0.5
-2 exposure = 0.25
-3 exposure = 0.125
etc.

Basically when you are talking in exposures, in terms of whole numbers, you are doubling or halving the amount of light.

Title: Re: Corona Color vs. Output
Post by: cjwidd on 2019-04-11, 04:32:50

Oh man, this is a really helpful explanation. Thank you so much!