How do I find out exactly whcih channels/render elements are saved in an exr file?
The only one I know of is a program called “exrheader” which you can download along with the OpenEXR sdk from http://www.openexr.org (you need the openexr-1.4.0-vs2005.zip file; in the bin folder you will find exrheader).
It can print various information about .exr files (channels, data format, compression etc).
Best regards,
Vlado