Lack of contrast

V-Ray V-Ray Common Gallery
1

Hi. I’m busy working on an residential interior project. An issue i’ve been having with it is that the image come out with a lack of contrast.

I’ve included an example - the first image is the render, and the second image is brightened in Photoshop.

I was wondering if someone could suggest a method to increase the contrast in the images. I have been considering using VrayPhysicalCam and VraySun, but i already have cameras set up for animation. I could redo the camera paths, but i was wondering if someone could recommend another method.
Is there a way to save the V-Ray buffer colours curve correction into an image?

700×495 30 KB

700×495 38.9 KB

2

i would try a differernt colormapping method. it looks a bit like HSV exponential (I still use this as well) which seems to require a bit of photoshopping in post to look good.

I’ve been using reinhard and adjusting the burn/gamma value’s recently which is working ok for me.

I think the main problem is that it isnt clear where the light sources are located and the interior seems very evenly lit. One solution (after reasons some other threads) may be to darken your materials slightly and increase the brightness of the REAL lights that you want to define. Either remove or tone down the general area/plane lights (not sure what you have used) so that they arnt competing with the real light sources that would actually dominate this space. The main ones are the window/door opening, the lights on the wall, light over dining room and kitchen - both of these should be defined.

I think your photoshop edit is looking ok but still has the underlying problem of lighting not being defined. I would expect to see more shadows (i dont mean pitch black ones) and more blown out areas but to get this effect i think you need to reduce the general ambient light sources and focus on the real ones, then bring the overall brightness of the image back up via colourmapping etc

Maybe an expert can tell you more, i just thought id help get things started.

3

Use dark (.5) materials and a realistic light scale. and use 1.6-1.8 gamma.

this example is very dark .255 materials - with 2.2 gamma
http://www.chaosgroup.com/forums/vbulletin/showthread.php?t=39210

and this one is .5 materials with 1.65 gamma.
http://www.chaosgroup.com/forums/vbulletin/showthread.php?t=41435

use the ‘output’ setting on bitmaps or other types of maps to make them dark.

4

I think even showing your lighting fixtures will add contrast to your scene.

That blank ceiling definitely not helping it.

5

@add101

To me it looks like wrong gamma settings. If you use the VFB - hit “display colors in sRGB space” and save as HDR file. When opening in Photoshop you should have the same colors as in VFB.

I find this tutorial from Flipside very useful when setting up gamma in Max: http://www.aversis.be/tutorials/vray/essential\_gamma\_01.htm You might need to adjust your light and camera settings after changing the gamma setup.

If you don´t have the time to change your workflow on the current project, then here is a very quick way to fix your first image in Photoshop. Use “Exposure” and apply the numbers from the image.

With a little extra tweaking in Photoshop you will get this:

Preisler

6

and next time, perhaps do use the physical cam, with the settings in there, it’s pretty easy to make nice pictures, as long as you model in realworld size, with correct light settings, correct materials. Personally I only use max gamma at 2.2, and no colormapping in vray at all…And I never had contrast problems which I could fix with the camera settings..