Switching to the Sunny-16 Technique, but have dark sky...

[RyanSpaulding]

Hey guys,

 

I've been using the lele method up until now to get accurate results with my VRay scenes. It for the most part did work, but I had issues with the image being too dark, and when I bumped up brightness with the ISO, my colors became washed out...which then had to have major color correction in PS to match the samples.

 

I've looked into the Sunny-16 rule and like the output a bit better, but the only thing not working is the sky...it's way too dark. For those who use the sunny-16 system...do you have a way to brighten just the sky up with some sort of multiplier? Or are you placing a plane with a sky bitmap in the background typically?

[Trevor Tizard]

Are you running SP1 of vray because I recall the dark sky issue was addressed from earlier versions.

 

Despite this I still add my Sky in post.

[Chad Warner]

The other thing you can do is copy the vraysky and apply it to your max environment slot and manually adjust it.

[jorisAR]

What is the sunny-16 technique?

[Fran]

http://en.wikipedia.org/wiki/Sunny_16_rule

[RyanSpaulding]

The other thing you can do is copy the vraysky and apply it to your max environment slot and manually adjust it.

 

Hmn. So how is this done?

[Chad Warner]

just check "manual sun node" in the sky's map slot, and you can adjust the intensity to whatever suits you. As long as you copied (not instanced) the sun, it won't effect Vray's environment map. (unless of course you're not using it in the VRay environment.

[BrianKitts]

I've been using the lele method up until now to get accurate results with my VRay scenes. It for the most part did work, but I had issues with the image being too dark, and when I bumped up brightness with the ISO, my colors became washed out...which then had to have major color correction in PS to match the samples.

 

sounds like you are doing way too much fudging.... are you doing any gamma correction? LWF?

[alfienoakes]

Agree with Brian here.. Sunny 16 with LWF should work a treat.. no more messing needed.

 

In fact sunny 16 on its own without LWF should look ok..

 

But also, Trevor is correct. Older versions of 1.5 did have a few issues with the sky. Make sure you are on the latest.

[RyanSpaulding]

just check "manual sun node" in the sky's map slot, and you can adjust the intensity to whatever suits you. As long as you copied (not instanced) the sun, it won't effect Vray's environment map. (unless of course you're not using it in the VRay environment.

 

Hey Chad, I forgot to thank you on this one. However, I'm noticing that when I do this, I'm actually adding more blue from the sky's intensity into the scene that bounces on other objects and am also getting slight bleeding in color due to more light hitting and bouncing.

 

Is there a way to just brighten the sky w/o adding more light? Sort of like a manual override.

[Trevor Tizard]

Could you not render an alpha channel to manually adjust the sky in post if you don't want it to add more light?

[RyanSpaulding]

I could for stills...in fact, I do for stills...however, we also do a decent amount of animation around here...so that issue still needs to be solved.

[alfienoakes]

if you drag your Vray sky from the environment slot, to the material editor, and instance it, you will see then all the settings for the sky. You can then choose your sky node, which is the vray sun in your scene.

 

A lot of settings and colours can be controlled from here. Also, if you are getting too much blue from the scene, change your vray physical camera settings for the white balance.

[RyanSpaulding]

That's exactly what I'm doing though. My white balance is a light orange hue (rgb = 251/218/175) btw. Camera is using the sunny 16 rule so it's all default except for f-stop (16) and iso (90). Sun is also default.

 

Ok, here's the process (using VRay 1.5 S1 btw):

 

1. Place sun (materials are accurate, bounces dont bleed, but sky is too dark)

2. I go to the environment tab, drag the sky to the material editor as an instance

3. Check 'manual sun node'

4. Increase the multiplier to 2

5. Render

 

This makes the sky the way I want it, but the blue it casts is now multiplied by 2. This creates a 'cold' feeling throughout the scene.

 

I'll render out some images to show what I'm talking about.

[Chad Warner]

It's a two step process. Instance the vray skymap out of the environment tab, but then clone it in the material editor. Drag the clone into the "override max environment" slot in the Vray settings Tab. Then you can change the original instance to manual sun mode, and change as you wish, but it won't effect the environment light, which is now being overridden by the clone.

 

This probably doesn't make much sense.

[RyanSpaulding]

^^ Interesting. I'll play with that one some more...it does make sense now...but only after that explanation.

 

Until then...here's the renders from before that may prove to be a non issue anyways.

[RyanSpaulding]

Well, it works great! Thanks!