DMC sampler infuences image brightness?

[biceboca]

I've recently encountered a stange thing.

If I'm raising my DMC sampler values for example from min 1/max 4, to min1 max 16, the image get generally darker. MOstly the shadows, and also the midtones. The Highlights stay on the same level.

 

Until now, I tought the dmc sampler and the subdivision sampler would only influence the antialiasing. If I raise it, I would have less noise, more detail, finer edges.

 

But on the scene I'm working now, it' somehow messed up, if I raise the values, my image will have more detail but also far more noise in the glossy reflections, and the shadow areas - and the shadows also get darker.

I'm lighting my outdoor scene with an HDRI, rendering with primary brute force, secondary light cache. Raising brute force subdivs will not help...

Is maybe my vray messed up somehow?

Thank for any help.

[Ismael]

Read

http://www.interstation3d.com/tutorials/vray_dmc_sampler/demistyfing_dmc.html

[Chris MacDonald]

^ exactly that.

[biceboca]

Thanks, i've read this article earlier - not an easy one. But what's the conclusion?

If I raise the subdivs in the adaptive dmc sampler, technically my image quality gets worse?

Should I also raise the glossiness subdivs in the materials? And also lower the noise treshold in the render settings, to remain on the same picture qualtity?

It's seems that this works somehow against me...

I'll be doing more tests. Honestly i'm rendering with vray since two years, but never encountered this "problem". In all the projects i've done (not so many) more subdivs in the render panel meant better picture quality and more rendertime, until now...

Anyway, thanks again. If anyone knows a similar article like the one above, please share.

[Ismael]

More stuff? How about RenderStuff?

http://renderstuff.com/free-rendering-cg-tutorials/

 

Read more.