V-Ray 2.0 incorrect Environment exposure control preview?

[miguelsantos]

Hi guys, I'm new here and new to V-ray too. My english is poor cause i'm still learning it (I'm brazilian) But I have a question that a can't find in the internet, and it's: why the preview of V-Ray 2.0 Exposure Control does not correspond to the final render, just like the mental ray exposure. I have tried the option exposure from vray camera, and the same thing happens. The preview is a lot diferent from the final render, the previw show a brighter scene, and when a render i get a dark image, it's make me crazy. Case the exposure it's affected for the settings of the control, but the preview it's aways diferent aways brighter. and I have to do a "render test" all the time. I interesting fact is, when I use the automatic exposure control, the preview shows the same light appearance of the render, but not the vray exposure. Please, someone can help-me?

[miguelsantos]

I also tried to do gamma corrections, and the final render is aways darker than the exposure control preview, both are affected by the gamma, but the preview is brighter, and when a use the "no exposure control" the render and the preview is the same. But the problem is whith the vray exposure control, and its happens also in the default settings and to new files. I start to thing that is normal and nobody use the preview, Can anyone test this? Tell-me if it's happens whith you too. Do a new file, place a plan or any shape and choose vray adv 2.0 as the render, render this withought the exposure control, and after, choose the vray exposure control on the envirement tab, do a preview render. And render a production render again, see if the preview is more brighter. It's true or it's only happens to me?

[Corey Beaulieu]

I can confirm that it does not only happen to you. The preview is not and should be used as a true sense of the exposure value. You are better off putting the noise threshold at 0.05 and light cache on 500 and rendering a 500x500 image. You don't even have to let it go all the way to the end. Light cache is a good view of things to come, just make sure you tick on "Show Calc".

[miguelsantos]

Thanks! I'm glad to hear that. I'll do what you say. Now I can see the calculation phase like in Vray for Sketchup! Thanks Again, and I hope Chaos Group to fix the preview, it's look useful when i use Mental Ray.