HDR differences?

Ralf1958

Hello everyone.
I bought two wonderful HDR Skies at CG-Source. Those are 16.000 x 8.000 px. They look fabulous and can be used without a backdrop picture. The shades and the light are awesome, the clouds are sharp and crisp and I am very happy in using them.
Unfortunately they are "just" skies and I was looking for an Environment map with a nice bright sun, some clouds and distant trees. On CG-Source I couldn't find what I was looking for, so I went for HDRMaps. I bought one in 20.000 x 10.000 px and was aspecting the same results as with the other HDRs.
Well... NO! This new Environment map puts the Scene into the right light but, as Backgroud it's way way way to bright. I tried to reduce the intensity but the result is that when the Background has the right brightness, the objects in the Scene appear to dark. So this Map is intended to be used with backdrops, which is not what I want. From some camera angle that is just looking weard.
Anybody here that can explain The difference in between those files?
I want to use HDR Environment map for lighting as well as for Backdrop, without using an extra backdrop Image.
Is there something I have to look at when I am buying These maps?
Thanks :-)

Ralf1958

Oh, I forgot, the last set contains as well a tone mapped Image. I tryed that one as well but even this one is Kind of overexposed.

Ralf1958

Here is what I mean. There is a huge difference in between those 2 HDRs. The HDR sky is easy to adjust but the HDR Environment is not. With the HDR Environment either the Background gets to bright or the set is getting to dark and the shadows aren't almost there. While with the HDR sky, shadows are nice and both, Background and set have a good lighting.
So, how do I make sure that the expensive file I am buying is giving me the result I want?

BeeMKay

I guess the one is meant for lighting purposes only, while the other can also be used as background?

Sorel

Maybe change the gamma? (i think that is a thing in iray?) I know in octane depending on the hdr I change it to either 1 or 2.2

Ralf1958

I helped myself out. :-)

I merged the files in Photoshop. I took the original nice looking sky as template. Then I copied the overexposed Environment into this file, adjusted the exposure and masked out the ugly sky. After I saved the whole Thing as a new HDR file and... tadaaa! It worked out perfectly, I got a nice sky and a nice Environment with shadows, the way I wanted it. Perfect for my purposal. I will upload a couple of pics in a few minutes. :-)

Ralf1958

Here we go... same Environment, 2 different skies. :-)