Tim_LIVID: Cheers!
The HDRI image is renderd in Maya with Mentalray... The basic scene setup is Maya Fluids for the water and then I have a skydome and I also use some fluids for the clouds... That is then renderd with a single camera in the center of the scene and taken into HDRShop for tweeking and to check the pixel values. I think the brightest pixel on my HDR image is around 1.8 and the lowest 0.4 from what I can remember.. Hope I answerd your question?

/Chris