correct Workflow with exposure?

[ce89]

Regarding setting up an interior or exterior scene I always tweaked the exposure as required having found a good balance between Sun and Sky. I have since had a few friends saying that exposure should be kept a 0 and tweak the Sun and Sky from there on as this makes for a more controlled scene with less blownout areas and less noise. Is this the case, I cant see any huge differences myself with some simple tests carried out? Are there any benefits/down sides to locking exposure to 0. Seems a bit counter productive, but just wanted to make sure I wasn't missing a trick.

Personally I like to work with as many constants in my workflow, but for me exposure is a complete variable, especially if used in a physical camera workflow.

Thank you for any feedback on the matter.

[Ondra]

to get correct results: lock sun intensity at 1 and sky intensity at 1. Use any image exposure you want

[ce89]

Ondra, thank you for the quick response. That makes a lot more sense than locking exposure at 0.

[maru]

I have since had a few friends saying that exposure should be kept a 0 and tweak the Sun and Sky from there on as this makes for a more controlled scene with less blownout areas and less noise.

Who told you that? :)

In Corona there is no difference if you set light intensity to 1 and exposure to 0 or light to 0.5 and exposure to 1. You can imagine lights as unitless and exposure simply determines whether they are brighter or darker.
Sun and sky are models, so intensity@1 corresponds to some measurable, physical values, so leaving this at 1 guarantees realistic results.

[ce89]

Maru,

Just believe when I say I have a hard time trying to pursued these friends, half the time it makes no sense at all so find myself trying to finding out the correct answer just to prove them wrong and then they don't always believe it anyway. Constant light values = constant material, light, env values to work with. I'll see how I get on explaining this one 😊!

[Juraj]

Strangest thing I've ever heard...

As Maru posted, mathematically it will all add up to the same, but adjusting lights simply makes far more sense.

Blow-outs are all matter of tone-mapping and art-direction as long as your materials have correct Albedo and specular levels. Some perspectives simply blow out more it has nothing to do with rendering setup,
I still don't understand why so many 3D artists think of it as some sort of mistake. It's absolutely natural and it's completely easy to treat it with normal solutions (adding highlights tonemapping in framebuffer, changing camera/light angle, adding flash lights/soft boxes into interior spaces like photographer would etc..).

But not some strange vodoo mumbo-jumbo with number. More intense Sun ? Who would ever come up with that ? And how... ?

Also noise is the same, as long as you start your final render with correct exposure before (don't render finals underxposed -5 or some other stupidity because you want to recover it later).