Getting that airy, light look for interiors

[piotrus3333]

my take on the scene.

vray sun/sky, override mat is 18% gray diffuse only, properly exposed should give you something not too far from 117 srgb in the image.

220 lumens bulb added in the corner.

vray defaults, tonemapped with curves and highlight burn (001.jpg).

highlight burn for the last little push, brought back even blue vraysky that was above 1000 float. not easy to access values like 1000 in vfb's curve editor..

I have to admit it that scenario

highlight burn is truly not enough - but better to mix it with curves than with low reinhard burn I guess.

photographer would probably just try to merge two or more exposures before dragging artificial lighting in. the efficient kind of lazy. but maybe not.
png file is 16bit log color saved from raw linear render. put photoshop curves on top. or different curve and than your lut.

end result is not that different but getting there is more straightforward that way imho. just add more windows or render it in something like more like studio environment not real interior - if I remember correctly this is product shot not interior design viz.

[piotrus3333]

but anyway, when the upped camera exposure doesn't give me good results with the lut, what would you do then (inside the VfB)?

highlight burn >> curves for contrast >> lut >> go back and adjust curves to compensate for crazy lut

or

curves (highlights and contrast) >> maybe highlight burn in extremes >>

lut >> go back and adjust curves to compensate for crazy lut

contrast slider can sometimes be sufficient for adding or removing contrast. exposure tab in vfb with its three sliders is your most basic tonemapping tool.

[DanSHP]

I think the LUT you are using isn't helping. The Kim Amland LUTs are pretty strong giving lots of contrast, especially 03 which is the strongest one. Do you use them at 100%? I'm no expert I should mention, just from my experience.

I use these from Adan Martin

https://www.youtube.com/watch?v=LVP-210q-fw&t=1243s (click show more for google drive link)

I use Porta 800 and soft/hard. The ektachrome's are pretty good for moody visuals.

[kosso_olli]

I'm not sure if this is what you are after, but here is a render of a scene I rendered quite some time ago.
This only has a LUT from the Corona installation applied, plus some contrast from the VFB controls. No further post production involved.
PhysCam with plausible settings, one domelight together with some artificial lights on the ceiling and the shelf in the background.

[MANUEL_MOUSIOL]

thanks, piotrus3333 for checking it out and testing. I have to say, even in your try the highlights are still burned out, so I am more and more thinking that at least in this example tonemapping is essential.
I am trying to avoid tonemapping in a different application cause it slows down everything. I love that right now I can just save out a test render, send it to the client and we both know how everything will look in the end. It will not be that hasslefree with tonemapping.

DanSHP thanks for the link! I will check out the LUTs. As far as I know the Kim Amland LUTs are Corona LUTs... 03 is giving higher contrast but that is more for darker shadows, highlights are not as strengthend. I was using 02 the whole time but for the last push in shadow contrast I switched to 03 at 100%.
As I said, up until now I never used LUTs, but they are very practical in a fast workflow I think it is harder to replicate the same with with curves. I didnt do any tests though, I have to say.

kosso_olli this looks very good. When you say that you just added the corona LUT and some contrast, what are you render settings? standard? or some reinhard burn taken down?
What are your material settings mostly? I am asking because there is very little burned out (if even), but I would guess that for this exposure you cranked up the dome pretty good, no?

[DanSHP]

thanks, piotrus3333 for checking it out and testing. I have to say, even in your try the highlights are still burned out, so I am more and more thinking that at least in this example tonemapping is essential.
I am trying to avoid tonemapping in a different application cause it slows down everything. I love that right now I can just save out a test render, send it to the client and we both know how everything will look in the end. It will not be that hasslefree with tonemapping.

DanSHP thanks for the link! I will check out the LUTs. As far as I know the Kim Amland LUTs are Corona LUTs... 03 is giving higher contrast but that is more for darker shadows, highlights are not as strengthend. I was using 02 the whole time but for the last push in shadow contrast I switched to 03 at 100%.
As I said, up until now I never used LUTs, but they are very practical in a fast workflow I think it is harder to replicate the same with with curves. I didnt do any tests though, I have to say.

kosso_olli this looks very good. When you say that you just added the corona LUT and some contrast, what are you render settings? standard? or some reinhard burn taken down?
What are your material settings mostly? I am asking because there is very little burned out (if even), but I would guess that for this exposure you cranked up the dome pretty good, no?

I thought you were looking for the opposite to shadows and contrast? Light and airy

[DanSHP]

my take on the scene.

vray sun/sky, override mat is 18% gray diffuse only, properly exposed should give you something not too far from 117 srgb in the image.

220 lumens bulb added in the corner.

vray defaults, tonemapped with curves and highlight burn (001.jpg).

highlight burn for the last little push, brought back even blue vraysky that was above 1000 float. not easy to access values like 1000 in vfb's curve editor..

I have to admit it that scenario

highlight burn is truly not enough - but better to mix it with curves than with low reinhard burn I guess.

photographer would probably just try to merge two or more exposures before dragging artificial lighting in. the efficient kind of lazy. but maybe not.
png file is 16bit log color saved from raw linear render. put photoshop curves on top. or different curve and than your lut.

end result is not that different but getting there is more straightforward that way imho. just add more windows or render it in something like more like studio environment not real interior - if I remember correctly this is product shot not interior design viz.

I really like the look of the log version generally, and in terms of post production possibilities! I can see why you suggested that now.

Can you explain the exact process in VFB to get it to this point? SRGB on? Convert LUT to LOG space? Do I have to use specific LUT's for LOG space (Norm/Linear) etc? Finally, you mentioned in your earlier post that this can only work in post if I do not use render passes in conjunction. I am understanding you correctly there?

[piotrus3333]

MANUEL_MOUSIOL everything here done in VFB. you can tackle all possible highlights that way (curves and/or highlight burn).

DanSHP that basically only makes sense in photoshop with limited floating point color support. save to 16bit png/tiff/whatever (gamma auto or 2.2). see attached. compositing is limited as render is no longer linear. lut: https://we.tl/t-EJjnmxuKlA

[DanSHP]

MANUEL_MOUSIOL everything here done in VFB. you can tackle all possible highlights that way (curves and/or highlight burn).

DanSHP that basically only makes sense in photoshop with limited floating point color support. save to 16bit png/tiff/whatever (gamma auto or 2.2). see attached. compositing is limited as render is no longer linear. lut: https://we.tl/t-EJjnmxuKlA

Thanks for this, is that the empty LUT you were talking about?

Hmm. Everything seems much more controlled using this method, I quite like it and there is still a lot range in the image.

[DanSHP]

I guess the question I have now is, how do I test render my scene in VFB following this method?

[kosso_olli]

kosso_olli this looks very good. When you say that you just added the corona LUT and some contrast, what are you render settings? standard? or some reinhard burn taken down?
What are your material settings mostly? I am asking because there is very little burned out (if even), but I would guess that for this exposure you cranked up the dome pretty good, no?

The white materials do not go above 235, the dark ones not below 10. The render settings are default V-Ray Next, didn't touch any of the the color mapping settings.
I used the photographic01 LUT from Corona, but in the linear versions posted over at their forums. Reduced contrast by -0.15 and set the highlight burn to 0.7 in the VFB, thats it. The image looks different when viewed in pure linear sRGB, there are loads of burnouts on the curtain, bedsheets and walls and TV. I don't care, because the end result is good
The physcam is taking care of the exposure.

[piotrus3333]

I guess the question I have now is, how do I test render my scene in VFB following this method?

turn off lut. use highlight burn and contrast sliders from exposure section of vfb to make the image look decent.

[DanSHP]

turn off lut. use highlight burn and contrast sliders from exposure section of vfb to make the image look decent.

Cheers

In my example, I saved out an existing linear render down to 16bit .exr with all VFB corrections off, excluding the LOG LUT you provided (set to log space, save image) and was met with the LOG low contrast look.

I took the said render into PS, Image -> Mode -> 16bits -> Exposure Gamma. I was able to correct the entire image using curves alone in 16 bit, with tons of range and have access to all 16 PS tools etc! Really quite amazing. Thumbs up!

A few questions!
Would it make any logical/techincal sense to apply another LUT via colour look up in post PS, if I want a certain look?
There is no way of utilizing other render passes?
Why does 16 bit in log space provide more range than 16 bit not in log space?

[kosso_olli]

Two additional images using the same technique as described above.

[piotrus3333]

Cheers

In my example, I saved out an existing linear render down to 16bit .exr with all VFB corrections off, excluding the LOG LUT you provided (set to log space, save image) and was met with the LOG low contrast look.

I took the said render into PS, Image -> Mode -> 16bits -> Exposure Gamma. I was able to correct the entire image using curves alone in 16 bit, with tons of range and have access to all 16 PS tools etc! Really quite amazing. Thumbs up!

A few questions!
Would it make any logical/techincal sense to apply another LUT via colour look up in post PS, if I want a certain look?
There is no way of utilizing other render passes?
Why does 16 bit in log space provide more range than 16 bit not in log space?

you are missing the whole point of avoiding 32bit mode in photoshop. without lut active in vfb the log space conversion is not happening.

if you like the lut than sure, use it.

it’s not about bit depth but high dynamic range raw render (like your exr) and low dynamic raw render (like my 16bit PNG). ldr being more convenient in photoshop.