Yup... I've just recently finished waiting about five, maybe six days for a spherical panorama of the Louvre in Paris to render out in Vue! So many days I lost track...

Rendered it at 12000 by 6000 pixels.

One big model of the Louvre in it... but otherwise, quite a simple sky etc... a few trees... and still took that long! But, worth the wait I think... it's just a case of getting on with other stuff meantime.

I've now developed the workflow where I render out a lo res copy in Vue first and use that on the envsphere whilst I compose my scene in Poser... and whilst waiting for the hi res panorama to complete.

I guess my question was whether IDL would be any faster if I made a lo res copy, just for IDL lighting, and then just used the full size as "visible in camera" for backdrop. I guessed it would be, a bit...

However, to be honest, for the example above, I've now set up my Poser scene and am rendering that at a dimension of 5120 pixels by 2560, and the IDL pass (with IC set at 50) is still pretty fast really, relative to how long the panorama took to render in Vue, certainly.

Raytraced reflections, even blurred ones, do probably benefit I guess from the hi res on the envsphere...

...depends on your composition and what reflections are needed in it, I suppose