Cinema - Post Effects advices

[DANIELE_CASAROLA]

hi!
First of all sorry for my english

There are 3 images in the attachement:

00_original: this is the original shot taken with a digital camera
01_vray: this is my attempt to reproduce the same room with same materials, structure, illumination and armchair (the armchair is a similar model but nevermind) using 3dsmax + vray
02_vray_photoshop: this is the vray rendered images modified into photoshop, increasing the "Contrast" slider

Well... obviously the work under a lot of point of view isn't perfect (shaders, geometry, illumination), but this doesn't matter, more or less I've reached what I was looking for (considering I've had few infos in input).
But what interest to me to understand is the big difference in contrast between image 00 and 01, and I hope someone will continue to read and help me in some way.
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...well, thank you
I assume this is due to "color mapping" values, so I expose in few words which are scene settings:
-Like the "Complete Vray Guide" (Francesco Legrenzi) explains, I work in Linear Workflow, this mean that (accordly with my monitor) under "Gamma and LUT" I've enabled Gamma with a value of 2.2, checked "affect color selector" and "affect material editor"; and finally set "Input Gamma" to 2.2 and "output gamma" to 1.0; I've enabled "Vray Frame Buffer", color mapping type to "Gamma Correction" with a "multiplier" and "gamma" set to 1.0 and "inverse gamma" to 0.454.
Those are always my start point for each scene.
-then I've modeled the scene, applied materials, insert a planar VrayLight on the top, enabled GI and rendered the scene. The image 01 is the result.

If you notice the image appears like if there is a sort of "fog" in front of the Camera, like a "grey filter".
I've tried to play with "color mapping" changing type, dark and bright multiplier but with not a good result. With a simple photoshop layer (brightness and contrast) I've increased contrast and the result is much better; but before to use photoshop like final solution, I'd like to better understand how Vray works.

I've noticed the same "effect" when I've made a test of different renderer engines: I've created the same scene (a studio light scene with few lights, a plane and a teapot geometry) using different render engines, and what I've noticed in Vray (that differs from other render engine) is that the vray output image is a little bit flat, there is this light grey effect that make the image to lose depth.

I thank you very much for your patient and I hope in some advice and explanation.

Thanks.

[flino2004]

it's pretty clear to me that the floor is transfering its color to the walls and ceiling, you could control it with vray override material. did you match all the setting from your digital camera to vraycamera?.
it's a nice exercise what you did... white wall space in my opinion is difficult to get directly without touching it in Photoshop

[DANIELE_CASAROLA]

thank you very much flino for have answering me. Yes I agree, it's a very good exercise try to reproduce shoots taken with a digital camera; it allows to better understand both the software and light behavior.
Anyway in my opinion it's the most difficult task: it's quite easy to start learning how a software works, what parameters and sliders do, but it's not easy manage these parameters accordly with "reality".

thanks again.