In this Black Spectacles free tutorial, you will learn how to bring rendered channels and rendered passes into Photoshop. I’m no expert at Vray and their “guides” and/or tutorials really only scratch the surface and don’t really explain every feature like they could.A free tutorial from the Black Spectacles course 3D Rendering with Vray 3.2 for SketchUp and Rhino 5. If you know your files are true and correct, something else may be causing a loss of light and the first thing I would check is your exposure settings in Vray, which I typically have to bounce back and forth between say 14 and 10 (for exterior and interior scenes respectively).

Overall though, I haven’t come across issues with IES lights not emitting like they should, and that may be due to the aforementioned file origination.

There are a LOT of IES lighting files floating around the net, some of which will trip your anti-virus as being a possible virus, so use caution on which ones you download to use, so as such, I only recommend getting IES files from lighting manufacturers. A good example is if you were to use Delta Lighting’s IES files, they will hold true to the lighting you use in your scene. As for unit conversions for lighting, I am unsure at the moment, since I haven’t had cause to use IES lights recently, however, when using IES lights, it’s important to have IES lighting files that are true and correct. Actually, and funny you should mention about the units conversion for Vray, that the latest update to Vray for Sketchup, they implemented code that automatically converts the units in the materials to inches from centimeters (as an example).

Sketchup vray photoshop