Auto-Exposure doesn’t work or not as expected. In real-world camera exposure is lowered when we have area directly exposed to Sun and exposure is increasing when we move to shadow area. In D5 it is completely not noticeable.
Years ago I made script for Cinema 4D that take into account relative direction between camera and Sun. If Camera is directed toward Sun, camera exposure is automatically increased by user’s given value.
I think that something like that should be implemented in D5 if calculating overall scene brightness is a problem - it is easy to do.
It looks that auto-exposure is too sensitive if it see dark areas and it prefer to overexposure even if whole view is too bright. This is why every people do underexposure :
This algorithm needs more tweaking. It probably use weighted camera view light strenght but it too much ignore strong lighting.
It should be more weighted on view center like vignetting than on whole view.
As I said before - it should takie into account sun position and prefer underexposure when Sun is behind camera.
Currently it do good job when we are in dark area or Sun is on front, toward us, but it do bad job if scene is directly lighted by Sun or other strong light.
I found something insane strange but in very positive way !
Auto exposure works very well but only using very high Sunlight and Sky Background powers. Just like above 500 and more. It looks so beautiful and filmic. I found new way to create insane lighting inside D5. I didn’t tested this using HDRI yet. I really don’t know why D5 use default values for Sun and Sky like 15 if using much higher values and auto-exposure do insane job ! Really WOW effect
I found that It works near perfectly just like high class real camera ! Also it increase looks of vegetation subsurface scattering. And especially GI light transmission. But it has problem to calculate proper scene brightness and it prefer to increase exposure when big bright area is visible like here :
Generally to trigger it’s effect it needs very strong lighting or environment power. It works for evening, sunset too but again - they must have power.
Now I know why D5 has such crazy Sun and Sky values in interface sliders. Default 15 is way too small for that.
Only one suggestion - most of the HDRI maps doesn’t have such power like custom D5 Sky and auto exposure needs it. Please add option to increase exposure for HDRI maps.
Or just please add more strength levels to HDRI Skylight. Sun strength max value is 20 while HDRI Skylight only 1. This is very big disproportion between them.
As I said before - autoexposure needs very intense lighting power to works correctly. Using standard Custom Sky values like 15 or current HDRI Skylight strength 0.5 it doesn’t work at all.
