CG artist Greg Zaal has announced that he plans to release a new free HDRI each week through his website HDRI Haven.
Signing up is not required although you’re encourage to do so in order to support the artist.
The first of the files, a shot of a bridge over a pond at night, can be downloaded here.
The HDRIs on HDRI Haven are typically outdoor scenes spanning a range of weather conditions, shot with a high number of exposure values, and are available at up to 16,384 x 8,192px resolution.
Feel free to check out HDRI Haven and their large library of HDRIs.