View Full Version : IES Lighting help required

08-12-2013, 08:55 AM
Help with IES lighting.....Pleeeeese

Can anybody help please,

I'm creating renders for alighting design company and have been asked to use IES lighting. I'm pretty cool with scene set ups and loading IES lighting data but my renders appear dark.

The lighting scheme I am using has been designed by the lighting company and the IES lights supplied by there chosen manufacturers, so I'm confident the scheme should be brighter.

To keep it simple the scene is a basement with no external light influences (although I will be doing a ground floor area with external 'shop front' light influence later and may ask about setting that up with correct levels)

Can any one advise regarding:

Diffuse settings on surfaces - its simple to ramp up the diffuse levels of the scene to get the lights looking brighter but I guess this isn't accurate as the client wants to see a simulation of the pre-designed lighting scheme.

IES lights import at a standard 50% Lightwave 'Light Intensit'y but also have an 'IES Brightness' slider which imports as Brightness 1.0 Is there a standard way to set these up so that I get real life lighting results to illustrate the lighting design as in the real world?

It seems there are many variables within the Lightwave environment which allow me to steer away from real life settings, this is great when setting up 'imaginary' images but confusing when trying to set up a real life lighting scenario....

Any help would be very much appreciated


08-12-2013, 10:57 AM
I've found that IES files are ALL over the place regarding intensity at LW 100% int. A couple I've used have needed to be boosted up to 1,000% - 3,000%!! So, tweak the light intensity until you get the desired brightness.

08-12-2013, 11:24 AM
As you probably know, Lightwave isn't set up to be 'physically accurate' so regardless of how accurate the IES settings are, they won't light a room the way their real life counterparts would on their own.
You'll most likely have to beef up the lighting as well as playing around with the radiosity settings. An Area light pointing up from the floor for example will help recreate the bounce effect of downlights.

If you're really struggling post the scene and we can have a look.

As a general rule, standard plaster walls work well at about 80% diffuse with some specularity. I'd only add subtle reflection and bump if you're going in close.

08-12-2013, 12:45 PM
all above is true. LW is not physically accurate. So your left with real world DATA that is not properly used. It's going to be a fake but you can get pretty close.

As far as adjusting radiosity I find that a few extra bounces help, but much pass that doesn't do it. Then I move to bumping up the actual intensity. Sometimes as much as 200-300%. this always brightens things up and then adds that feeling of 50+ bounces of light.

Good luck.