Big color differences when using Vray Physical Cam and exposure

[scottsch]

Sorry if this has been posted before, I've just started using vray+3dsmax from Soft/mental ray so some of my 3dsmax questions may be really basic.

Just started using VRay physical cam to adjust exposure and it is great in the final renders. Using the camera for exposure adjustment is the way to go. I just tried using it with RT and the exposure is wildly different - a normal exposure in the final VRay render is almost black (underexposed) in the RT view. This occurs when you click the "exposure" button on/off to activate this feature in the camera.

Known issue? I'd post pics but it's easy to visualize - the RT picture is almost black, the regular rendering looks properly exposed. 3dsmax & vray color mapping Gamma settings have been setup to the "standard", based on what everyone else is doing.

The only workaround I see is to forget about using VrayPhysicalCam for exposure and go back to adjusting lights and the tone mapper.

Thanks.

[vlado]

There is a known issue if the camera type is not set to "Still camera"

Best regards,
Vlado

[scottsch]

Hi Vlado,

It was set to still cam but it seems to be scene related because the color differences are also there with the regular 3dsmax camera. I think it is the portal lights... RT doesn't seem to "see" them, which makes the interior room very dark, compared to the regular VRay rendering which takes the portal lights into account. Still trying different things but I think this is this issue.

Edit: found the problem.... the scene had some lights set to "store with irradiance map", which made them invisible to RT, which made it look like an exposure issue. There was also a problem with RT not recognizing the exclude list. The lights were set to exclude the lampshades from having shadows cast onto them. VRay saw the exclusions but RT did not. Pretty easy to work around, though.