Fresnel Reflections and Material intensity

[trixian]

This needs to be pointed out: There is no checklist or hoops to jump through regarding LWF if you only understand what is going on, and why.
Obviously it is going to seem confusing if you don't understand it (obvious claim is obvious), but as soon as you get a grip on the whole concept, there are no more problems or surprises than working the old way.

True, there are still some aspects of max that make you have to consider things before going ahead, some Vray legacy UI stuff from the days before this being standardised that might seem confusing the first time, and issues like procedurals not adhering to the same gamma parameter as bitmaps, but at the end of the day, working the old way still makes you do things "wrong" and leads to you having to correct stuff either in max or in post anyway. I have never ever gamma corrected any bitmap through a CC map. I always do the gamma adjustments on the bitmap load dialogue when loading something that gets interpreted wrong.
(There is no rule that certain bitmaps need or don't need to be gamma corrected in regards to what slot they are meant for. The only thing that matters is whether or not the map is a gamma corrected bitmap, linear bitmap, or a linear procedural).
The big difference being with LWF, is you at least get a result that is somewhat predictable and doesn't rely on weird maths in the compositing stage amongst others.
Make your self a pre-set (maxstart file or render preset) and you should be set for the time being.

Also @ samuel_bubat: Cameras (dslr's)are usually writing to their own proprietary format,as raw, with some colour mapping, or to jpg as sRGB. Old analogue cameras were as non-linear as they come, hence the crazy LUTs one needed to read them properly when scanning the negative.

[joconnell]

There are three big factors in this - what is the camera seeing, what colour was the wall you're trying to match and how bright wa the light source hitting it/ You'll need at least 2 of those measurements or you're in a never ending cycle of tweak, render and so on. There's a really good fx phd course called mya 214 which is actually a maya and mental ray course done by the head of 3d in framestore that goes into shooting reference on set to allow you to calibrate hdr's and brightness values so that you can get your camera and hdr in a really accurate place, so with those two parts of the equation locked down, all you need to do is get your material looking right.

A lot of games have moved towards physical based lighting recently and as part of that they've started scanning materials to get an accurate idea of how bright the diffuse really is, how reflective they are and how blurry their reflections / speculars are. There's a good article on http://www.fxguide.com/featured/game...-me-rendering/ which runs through it and even shows some charts with typical brightness values for common materials and their specular and reflection values. Again they're taken from specific objects so they're only 100% accurate to just those objects, but it's a far better starting place rather than picking a brightness value out of thin air.

[DPS]

@Joconnel - any idea where I can learn to calibrate my panos without doing the FXphd course?

I have been grabbing the metadata from one of my stitched photos and inputting that into vray exposure control. Then adjusting the HDR intensity and basically eyeballing it until it looks about the same as my control photograph.

Also I agree with others that without gamma correcting swatches - this test is off.