I made some custom HDR skies today. When I did my test renders the light intensity was waaaaaaay off. After some poking around, I found the problem. Photostop CC(2015) is reading and saving EXR files wrong somehow. Photoshop is clamping everything over +16.41 intensity down to +16.41. I'll post some of my test results bellow so you can see what I'm talking about. My workaround right now is to save stuff as .hdr.
I just wanted to give you guys a heads-up so you don't clamp your images, save as .hdr from Photoshop.
I have tried every exr compression method, same result.
For this test I made a HDR of Corona Sun/Sky, 7070x3535px.

Real Corona Sun/Sky

HDR saved from framebuffer as EXR

HDR saved from framebuffer as HDR

HDR re-saved from Photostop CC(2015) as HDR

HDR re-saved from Photostop CC(2015) as EXR

Look at this
shit, terrible.
Here are the values when you save from framebuffer or save from Photoshop as HDR

Here are the values when you save from Photoshop as EXR
