Once an HDRI is loaded into the IBL Lab of Bryce, there is no way of knowing the name of the file that was loaded. This is a serious drawback of Bryce 6.1 IBL. The thumbnails shown here are screenshots of loaded light-probes along with the Intensity setting used.
Tip: if the sun is not used in an IBL-lit setup, the sun Azimuth can be positioned like the HDRI X is and the sun's Altitude to the HDRI's Y. Under certain circumstances, the HDRI rotation and tilt settings get lost in the Bryce 6.1 source file. They can then be set to the sun's position, which is reliably saved.
Thumbnail list of Artificially created HDRI's for Bryce IBL, includes the Moon HDRI's.
Thumbnail list of HDRI's created with Bryce for Bryce IBL.
Thumbnail list of HDRI's created from Indoor photographs of a mirror ball for Bryce IBL.
Thumbnail list of HDRI's created from Outdoor photographs of a mirror ball for Bryce IBL.
Thumbnail list of HDRI's created from Photographs. These are not light probes as such, just squarred pictures for Bryce IBL.