Realistic light values and camera settings for day/night shots

[Ivaylo Katev]

My sneaky plan is so that anyone doing vfx can buy a can of the same spray paint, anywhere in the world, and create a grey ball that they can photograph as reference and then use the vrscan shader as a pretty close reference to calibrate their hdri's with. I know there's small variations between batches of a paint colour so this still some inaccuracy but it'd be better than nothing!

well, no problem to scan your samples, the service is operating with small orders too.

[kosso_olli]

My sneaky plan is so that anyone doing vfx can buy a can of the same spray paint, anywhere in the world, and create a grey ball that they can photograph as reference and then use the vrscan shader as a pretty close reference to calibrate their hdri's with. I know there's small variations between batches of a paint colour so this still some inaccuracy but it'd be better than nothing!

Well, I have to admit this is an excellent idea!

[garipodelu]

We have had issues judging this too. Take a look at the HDRI pack below.

https://3dcollective.es/en/producto/...2pack-pro-eng/

Each HDRI gives you a specific multiplier value (8,16,32 etc). Those that do not have a multiplier value are ok set to 1. I'd recommend reading how and why these values are used for each HDRI, it's all there in the link provided.

So with the multiplier out of the way, it's just the camera exposure to adjust, and to ensure all materials aren't too light or too dark.

I know about them Dan and we're currently using them.
Despite having good quality I found myself messing with the recommended multiplier too often because I don't think it's quite correct.
Take a look at my previous post with the two images where in fact I'm using one of the HDRs from that pack.
The one with the visible interior lights has a the exposure set to one, and the second image where the interior is almost pitch black has the recommended multiplier from the guys from 3Dcollective.
Which one do you find to be better? (keep in mind that the lights have real world values and colors).

[piotrus3333]

garipodelu you can not trust environment maps. never. calibrate to VRaySun/Sky. calibration process needs some ideal sample to match to. you can create a lot of daylight scenarios with that.
my only gripe about VRaySun is default turbidity that seems bit low.
good read:
https://cgg.mff.cuni.cz/projects/Sky...int_lowres.pdf

[Undersky]

My sneaky plan is so that anyone doing vfx can buy a can of the same spray paint, anywhere in the world, and create a grey ball that they can photograph as reference and then use the vrscan shader as a pretty close reference to calibrate their hdri's with. I know there's small variations between batches of a paint colour so this still some inaccuracy but it'd be better than nothing!

Great, so Chaosgroup's giveaways at conventions and gatherings will be buckets of paint from now on, thanks a lot!