HDRI Lighting: .HDR or .EXR?

[FutureMan]

Well what do you think is the better format for hdri lighting?

Personally I think they are about equal, however I seem to get much better results with the .Exr's I have and Vray. Although the .hdr's I have aren't that great so maybe that is my problem.

So is there any difference or it doesn't matter?

I also saw the review Metin 7 did of the Sachform collections over on Vray.info, in what format would you get those collections in?

Also what about the openexr plugin for photoshop? It works but I'm not very good in photoshop so I don't use it much, anyone here put it to a good use?

[Wolf S]

For lighting they should give the same results. The only different is that the EXRs are lossless compressed.
If you can output and work with EXR it is much better than HDR because it can hold many other channels beside the color... like Z-Buffer, Alpha and such stuff.

Wolf

... http://www.sachform.de HDRIbase rulez

[Dschaga]

oExr is the future.

The only problem is, that you can't create oExr's on windows in the way you can create hdrs.
Photogenetics have some beta plugin, but if you want to create oExr you have to use linux ,osx or use max to convert hdris to oExr.

When there is a solution for that problem, then hdri is gone.

The main advantage of oExr is the fact that you can use different channels. On the lightbox we disscussed how oExr can be used in a clever way to have a smallsized hdr (for lighting) and a bigsized ldr (for the bg rendering) .
I still think that all hdrs with size of about 3000x1500px are not perfect in terms of using it together for lighting and for bg images.
You only need a small (maybe blurred) hdr for lighting which uses less memory and a very big ldr for the BG rendered image...

An hdr with 3000x1500 uses to much memory and brings the same range than a 256x128 hdr and nearly the same result.

The only hdrs which can be used for BG images too are the new ones from Dosch with 15000x7500px ..some time ago i got a cd from spherion and recognised that this is it... it's a 15k euro scanner which gives you impressive range at a size far beyond good and bad.

[egz]

You would want a hires HDR for reflections though, since HDR reflections look a lot better than LDR ones.

[Dschaga]

that's true...