# Openexr and Vray HDRI **URL:** \ **Category:** General\ **Created:** [November 30, 2009, 11:15pm UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530 "2009-11-30T23:15:02Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![rajdarge](https://avatars.discourse-cdn.com/v4/letter/r/59ef9b/32.png) [@rajdarge](https://forums.chaos.com/u/rajdarge)\ **Post date:** [November 30, 2009, 11:15pm UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530/1 "2009-11-30T23:15:02Z")
Using the dome vray light - is there any advantage in using the VrayHDRI as the texture map for the light over using a EXR through the bitmap (making sure its a true 32 bit bitmap)? Using the standard Max bitmap has advantages as all the HDRI panos that I have made I store in openEXR so I don’t need to convert them (they are very large). the workflow is slightly different with convolving the bitmap but the result is the same as far as I can tell. the Multiplier function: what does the multiplication factor actually mean: is 2.0 a stop above 1.0 ? ---
**Author:** ![rivoli](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/rivoli/32/44395_2.png) [@rivoli](https://forums.chaos.com/u/rivoli)\ **Post date:** [December 1, 2009, 10:05am UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530/2 "2009-12-01T10:05:08Z")
actually you don’t need to convert an exr to radiance before loading it in a vrayhdr map. exrs will work just fine as they are. ---
**Author:** ![rajdarge](https://avatars.discourse-cdn.com/v4/letter/r/59ef9b/32.png) [@rajdarge](https://forums.chaos.com/u/rajdarge)\ **Post date:** [December 1, 2009, 11:21am UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530/3 "2009-12-01T11:21:39Z")
wow thanks for that. It is very interesting information indeed. Wish I’d been smart enough to know that before - would have saved me a lot of time with the conversion thingy. ---
**Author:** ![rajdarge](https://avatars.discourse-cdn.com/v4/letter/r/59ef9b/32.png) [@rajdarge](https://forums.chaos.com/u/rajdarge)\ **Post date:** [December 2, 2009, 12:23am UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530/4 "2009-12-02T00:23:41Z")
actually I just tried it - and it didn’t work. It will only load HDR’s AFAIK ---
**Author:** ![BBB3](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/bbb3/32/58232_2.png) [@BBB3](https://forums.chaos.com/u/BBB3)\ **Post date:** [December 2, 2009, 8:40am UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530/5 "2009-12-02T08:40:57Z")
You can’t load exrs in the VrayHDR map. I discussed this with PGuthrie a while back and his view was that using exrs in a bitmap worked just as well, if not better. The few tests I’ve made seem to confirm this. ---
**Author:** ![rivoli](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/rivoli/32/44395_2.png) [@rivoli](https://forums.chaos.com/u/rivoli)\ **Post date:** [December 2, 2009, 11:15am UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530/6 "2009-12-02T11:15:53Z")
you’re right, sorry I posted that without double checking it. don’t know why I was sure they did work, but as you say they don’t. ---
**Author:** ![rajdarge](https://avatars.discourse-cdn.com/v4/letter/r/59ef9b/32.png) [@rajdarge](https://forums.chaos.com/u/rajdarge)\ **Post date:** [December 2, 2009, 1:07pm UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530/7 "2009-12-02T13:07:00Z")
yes using the RGBA32bitmap is just as good But what does the mulitplication factor mean? ---
**Author:** ![simmsimaging](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/simmsimaging/32/49287_2.png) [@simmsimaging](https://forums.chaos.com/u/simmsimaging)\ **Post date:** [December 3, 2009, 1:09am UTC](https://forums.chaos.com/t/openexr-and-vray-hdri/22530/8 "2009-12-03T01:09:04Z")
> [@NEXILIS](#): > > You can’t load exrs in the VrayHDR map. I discussed this with PGuthrie a while back and his view was that using exrs in a bitmap worked just as well, if not better. The few tests I’ve made seem to confirm this. The only thing I miss is the vertical rotation from the VrayHDR loader. That is handy, and the vertical offset in the bitmap loader does seem to do the same thing. b