Brute force Test Very slow :(

[piotrus3333]

one more thing comes to mind: how to quick-fix noise in too dark shaders - rise the gamma in color mapping. It's an old trick but should still work to some degree - it skewes the way vray sees dark colors.

[PIXELBOX_SRO]

so for a general usage well build shader used for exterior and interior whets the best range.
I like gettgin the most out of the render without having to color correct but is i use something like 10-15 for a black and 200-215 for white, then following the good physical values for exposures and lighting i get the blacks very unusable without color correction and tone mapping.

What is the correct workflow then?
Using 10-15 for black woudl basically mean redoing all our assets (speaking about TB of data)....but the output is not worth it as the black come out ugly as hell - not to mention when some reflection is applied on top.

And by the way - how do the albedo values translate into RGB values???

Cheers

M

[piotrus3333]

sure, renders will have "milky" blacks. sure, renders need tone mapping and color grading to look like photos. redoing assets? well, same thing happened when linear workflow was introduced to broader public. just simple progress.

albedo to color swatch? use vray color map - this should be basic color input for vray if you need precision.

[PIXELBOX_SRO]

sure, renders will have "milky" blacks. sure, renders need tone mapping and color grading to look like photos. redoing assets? well, same thing happened when linear workflow was introduced to broader public. just simple progress.

albedo to color swatch? use vray color map - this should be basic color input for vray if you need precision.

ah...did not know albedo is set in linear values.....DOH

[piotrus3333]

its % of reflected light. for example 18% gray card used in photography has diffuse value 0,18 in VRayColorMap or 46 in 3ds max color swatch.

[PIXELBOX_SRO]

Right thanks for the pointer...i tried testing the new values in one simple interior today with whites between 190-210 and blacks around 10 with ev set to 8 i was surprised how much vray sun still burns the whites even when set to 0.2 multiplier....of course without using vray correction tools. So with these setting i was able then to grade the image to get some nicer blacks back while keeping the whites around 1 float or right under it. I will have to explore this in more situations....
...for exteriors, the black value of 10 becomes quite unusable being very gray.

so how do you guys do it when you have a vizualisation that covers both interior and exterior? Do you have two types of black even if its the same kind of material? I seriously doubt that

I am fine with white levels but the blacks really do my headin

[piotrus3333]

heh, one blackest black is enough.
in mixed scenes (interior/exterior) it is even more important to use realistic lights. power and color from manufacturers data, simple as that. render that through realistic camera, tonemap it, grade it and done.

[PIXELBOX_SRO]

i could sign under that BUT it comes down to question whether sun multiplier at 1 is really correct
As far as i ve seen most of the people here on the forum always tweak the sun power to certain extent.
And since the exposure tables have been here quite forever, i take them as rule of thumb - therefore i am a little surprised the vrays sunlight at default setting still creates so much burn even on dark materials and completely overexposing whites set to quite decent levels ranging from 180 to 210.

Anyway, here is and example from my test setup which focuses on indirect bounced sunlight:

the 3 balls are these color swatches: 128 gray, 210 white, 10 black
table is 10-15 black

even if i grade the render, the "black" ball is still missing a bit of the blackness - however - i am happy wiht the table blackness which has a little reflection/specular added to it

[piotrus3333]

do not compare raw vray sun renders with photos tonemaped by camera. vray sun needs reinhard compresion.

[Rens]

Also VRaySun is set up to be rendered with VrayCam set to correct exposure levels.

[piotrus3333]

I also recommend getting a set of gray cards, some pocket versions and just shoot some photos. these have known albedo values so it is easy to recreate them in renderer.

[PIXELBOX_SRO]

RENS:

so are you saying the EV value of 7-8 is not correct for a daylight interior?

i am using Physical Camera .....its not meant to work with Vray sun Rens?
The only camera with exposure settings left in the creation tab is Physical - i doubt Vlado would let people using script to bring it back?????


What other values rather than those i have in my example interior should i use?
As far as i know it is recommended to use something between 4-8 depending on the situation/setting

PIOTRUS:

i was just setting an example on correctly exposed interior where the raw black value is within the recommended ranges, yet when you do the tonemap and grading you coudl still tell the blackness of the material could be a little lower, perhaps between 5-10 initially

I have left out all the camera values and detailed settings out of equation on purpose and used a EVs for exposure.....are you guys proposing this is not correct?


VLADO:

if youre reading this, could you please elaborate on what Rens is suggesting?


Cheers!
M

[Rens]

Hi Martin, yes sorry I mean the Physical camera. I can have a look for some standard settings for you tomorrow, but basically what I meant was that if you set the camera to settings you would use on a real-life camera, then VRaySun would (roughly) match what you would see in real life as as well. Though the intensity of the sun can vary a lot depending on clouds and other atmospheric conditions. Using realistic values for the camera and materials will ultimately get you in a range where you could just tweak the lighting intensity to get the look you want. It's just to get you easier in a range that is repeatable across scenes and simple to set up.

[PIXELBOX_SRO]

Hi Rens,
thanks that would be really great and i really appreciate it!
I got used to working with EVs nowadays as it lets me tweak apeture and shutter without affecting the exposure. I thought my EVs for interior were standard as i was always using this table:

https://en.wikipedia.org/wiki/Exposure_value

Looking to your input!
Thanks!

[piotrus3333]

i was just setting an example on correctly exposed interior where the raw black value is within the recommended ranges, yet when you do the tonemap and grading you coudl still tell the blackness of the material could be a little lower, perhaps between 5-10 initially

M

what does your grading look like? highlight compression and curves should be enough to get decent looking image from VFB.