[Frances]

Hi,

Your thumbnail views are all linked to the current page. It's hard to see what's what without the larger views.

[Mihai]

What is the color value of the walls?

What makes you say the light distribution is not accurate? Because of the darkness of the image? You can simply adjust your camera settings to make it brighter, but in this case I think also make the wall materials brighter.

Since metals also make caustics, that will contribute to the noise unfortunately.

About IES, it's wrong to think this feature alone will provide amazing accuracy. A post by another member a while I ago I thought was interesting:

In the creation of relative photometry polar distributions (from which .ies files are derived) the intensities are read at a distance of at least 5 times the maximum fixture dimension.

When you use any ies light nearer to a surface than this distance, what you'll see is at best vague.

Maxwell, however, traces ALL light interactions between surfaces. So as long as your emitter resembles the lamp element in size and shape and your reflector/refractor geometry & materials are right you see all the subtle elements of a distribution that gets lost in an ies file.

So if you want to be really accurate you could model the fixture if you have the exact dimensions, but IES would be nice to have also, as a convenience.

[Mihai]

Ok, then brighten up your concrete texture a little bit.

You can just turn off direct and indirect reflection caustics if you don't really need to see caustics from the metal parts. Don't know how much subtlety they contribute in this case but I think turning them off will give you much less noise.

Not sure I understand when you say the fixtures are close to the IES you used. IES doesn't make geometry for you, just gives the renderer some falloff values for the lights, so using Max the geometry of your fixtures could have looked like anything. If you use the same IES profile, the light distribution would be the same. In Maxwell though you would need to actually accurately model the geometry of the fixtures to ressemble the real one. Or one that looks good