These .hdr files are optimally for use in a program like 3D Studio Max, so don't download the pack if you don't have a program that can utilize a .hdr file.

Photoshop cannot open a .hdr file (unless in the rare instance you've installed Microsoft's Direct X 9 Software Developer's Kit, not normal Direct X 9), and you have the proper .8bi filters in your photoshop plugins folder. It's 99.9% likely, you don't have this.

They were submitted to this section because:
1.) they are to be imported into a 3d program.
2.) avoid being in "textures," where multitudes of people would probably DL them, and not know what to do with them.

As I said, they are meant for use in a 3d program, not an image editing program, so don't download them unless you know what to do with them.

After spending much time looking online for some decent HDRI maps, and only aquiring a couple decent looking ones, that were 512's, I just decided to make my own. I made a batch of about 100 or so 1024's, ranging from low environments, to high, mostly photorealistic ones (from personal photos, and stocks), all sticthed manually. They have some minor errors here and there on some of them, but for what I use them for, they work more than fine enough. All of the images have been exposed and marked, so you shouldn't have to adjust the Black & White (Point/Clamp)'s. That is to say, if you don't adjust them, you'll get results like those on the spheres above. Since the only stipulation of some of the stocks that were used is to not use them in commercial works, that stands here too. No selling of anything these are used in, respectively.