hdri background images

I think it's probably that the map is wrapped around the entire scene, and it 
wasn't intended to be.


If the HDRI is a regular photographic view, and not a reflection in a chrome 
sphere, a lat/long conversion, or a view through a fish-eye lens, it's not 
really usable in 3D (for background or lighting purposes, anyway) unless 
you map it onto a card. If your HDRI is distorted in ways that regular 
photographs aren't, it's intended to wrap all the way around your scene, and
that 
means you can't really zoom in or out.


Many HDRI look like regular photos, but with extra information in the 
brightest parts. HDRI like these are not intended for use as environment maps in

3D, but are intended to show the benefits of HDRI in 2D, or to demonstrate 
certain technical concepts in the acquisition & manipulation of HDRI.