Attached Link: What Now?

The thing about using lower-resolution images is that they don't take as long to render if you're using Vue to create them.  I find that if I make a low-res spherical image for the environment sphere (just for lighting) and then a higher resolution flat image to use as a background in Poser, it takes less rendering time.

However, if you want to use depth of field, a background photo has to be manipulated to produce the effect.  The attached image, for example, uses a high resolution HDR image on BB's environment sphere.  I played around with Poser's depth of field setting to get the background slightly out of focus.  Rendering that background took DAYS in Vue, but I like the results.