Gamma + tonemapped EXR's

[neepneep]

I'm not sure if this is a bug but after exporting tonemapped EXR's I always find I have to halve the gamma with Photoshop (more like 46%) to get the EXR to look the same as the indigo output window & the PNG.

It's not that serious of an issue - more of an annoyance, but I'm sure it puts a lot of people off using tonemapped EXR's because the output is not as one expects

[alex22]

The exact value could be 1/2.2, since 2.2 is the gamma value most monitors use. The higher the gamma value, the darker the picture gets. You probably just changed the gamma from 1 to ~2.2.

[Kram1032]

so the accurate gamma would be 0,4545454545454545.......

[neepneep]

ah that would definitely explain it... ! thanks alextwentytwo!

[CTZn]

and that leads us to the conclusion that there is some reverse gamma correction missing... Mmmh, bug ?

[Kram1032]

not quite I guess....
I somewhere read, that gamma gets less and less useful, with increasing bit-depth of colour.
Gamma basically distorts the colours sothat less information is lost in dark spots where noone can see it anyway and more of it is found in the brighter, easier distinquishable parts of a picture.

For 256 colours/channel, that's very useful...
For 65536 cpc, it's still quite useful (16bit images)
but for float 32-bit, it's probably not really nessecairy.....

[CTZn]

Number of colors and light dynamics balance are certainly correlated, but I think gamma could be necessary because users expect that ?

[Kram1032]

true ^^

[Zom-B]

I complained about this years ago, but nobody listened

Maybe this is also a result about the few extra pixels in size the exr have compared to your output settings