Corona balancing light automatically

[DarcTheo]

Got a problem in one of the scenes where no matter what happens, corona balances the light back to a standard level.

If we try to over expose the scene with interactive it starts overexposed then brings it back to the middle ground. If we under expose it starts black and then levels it back again. Basically we cant seem to adjust the lighting at all because corona keeps levelling it out.

Is this a new thing? some check box accidently hit?

Going to try using in a different scene to fix it.

max 2016 and corona 1.4

[pokoy]

Maybe you have some exposure control enabled? I have no clue if and how the built-in exposure in 3dsmax may interfere but make sure it's set to 'none' under the standard exposure settings so it's left to Corona only.

[DarcTheo]

it using physical camera exposure controls. It is now responding to the settings but it appears to be clamped at a certain point. Cant purposely over expose the scene beyond a point.

Tried the shutter speed to something like 10 seconds with ISO 8000 and f stop at 1, anything to try n expose it but it seems its locked. Strange as I thought you should be able to make it go pure white, obviously not the result wanted but we cant actually reach that stage.

[pokoy]

I guess it's advisable to disable any built-in exposure control and rely only on Corona's settings, this will be the most predictable and stable workflow.

[maru]

Maybe it's another case of this?
https://coronarenderer.freshdesk.com/support/solutions/articles/5000517899

You could easily check that by changing MSI to 0.

Also, didn't you touch System > Higliht clamping?
What is your highlight compression value?

[DarcTheo]

Maybe it's another case of this?
https://coronarenderer.freshdesk.com/support/solutions/articles/5000517899

You could easily check that by changing MSI to 0.

Also, didn't you touch System > Higliht clamping?
What is your highlight compression value?

system highlight clamp is at 0. and the standard VFB highlight compress is at 1.0 default.

Maybe it is this MSI, the scene they are working on (its not my project) has some direct light but is relying on alot of bounce light i suppose. Increasing MSI or using MSI of 0 should make the overall interior feel brighter with a trade off of more noise to clean?

[DarcTheo]

another thing i just noticed is when saving VFB history changing the exposure changed the exposure on my VFB history :/ why? how? what o.O

[PROH]

Hi DarcTheo. When you say you use the Physical Camera Exposure control, do you then mean the one in Max's environment panel? If so, then you're basically using two exposure controls: 1 in Max + 1 in Corona.

I don't know exactly how well/bad Corona works with Max's different build in exposure controls, but the few times I've tried to use both, I went back to only using Coronas exposure control in order to get reliable/predictable results.

[DarcTheo]

Hi DarcTheo. When you say you use the Physical Camera Exposure control, do you then mean the one in Max's environment panel? If so, then you're basically using two exposure controls: 1 in Max + 1 in Corona.

I don't know exactly how well/bad Corona works with Max's different build in exposure controls, but the few times I've tried to use both, I went back to only using Coronas exposure control in order to get reliable/predictable results.

I did turn off the envrionment physical camera exposure and used just corona cam modifier to control the exposure but the same thing happened either way. I've not had a problem just using physical cam before but i'll just make sure to add a corona modifier each time from now on just in case and turn off the physical camera exposure in environment.

We often struggle with trying to get a natural lit interior when theres not much room for direct sunlight. I feel like theres enough for a light room but it just never feels light. this is first time ive seen corona hold back the exposure as well. bit confused on whats happened tbh :s