Can having a lighter coloured (paper roll) background make rendering take longer?

bevdog896_d08d9c913a

So as a lighter coloured background creates more light will it contribute to increasing render times? 

fastbike1

I haven't seen that effect.

XoechZ

I think more important than the color is the glossiness. If your backdrop is very glossy and therefore reflects a lot of light that falls back on your figure or whatever, than the render could be slower than with a matte background that does not reflect light. But this is just guessing, I am not sure about this.

DAZ_Spooky

Iray vs. 3Delight. Iray more light sources, to include reflectors, generally means faster render times. 3Delight more lights, and especially reflected light, means longer render times.

DestinysGarden

I have not noticed any increase in render times depending on the background color either. Having a bump and normal map on the backdrop can really increase it, depending on the other lights, as the renderer has to calculate all the little shadows on the backdrop.

XoechZ

I cant speak for 3Delight or Iray, because I am a Reality/Lux user. But from there I know that when I use a paperroll backdrop and set the material to "glossy", the render takes more time to clear up than when I set the material to "matte". This is because the render engine has more calculations to do, no matter how many light sources I use. The difference is not dramatical but definitely noteable.

And, as DestinysGarden said, if the backdrop contains some bump/displacement, there are even more calculations to do for the render engine.

Now, going back to the initial question, my experience is that the material settings of a backdrop have more influence on render times than its color. So, if you use a medium glossy backdrop there should not be a difference if it is light grey, dark gray, blue, red or whatever.

bevdog896_d08d9c913a

Thanks for the info guys