LUTs: Powerful Color Correction - The Guide

1) use unsupported, alpha software I accidentally leaked
2) discover there are problems
3) wonder why

Marty, I realize you didn't mean for this to get out into the public but I must say it's become an invaluable tool for me when creating my LUTs. The fact that it replaces Curves, Levels, Tonemap, etc. is a godsend. I've been able to achieve much more nuanced looks by being able to control the exposure and saturation of individual colors. For instance being able to single out and manipulate the color orange has given me much more natural looking skin tones.



I've been using it for a few weeks now and I haven't encountered a single issue. As a former graphic designer it's very intuitive. Of course I also realize the down side of trying to play "tech support" to people who are easily confused by any sort of image editing. I really wish you'd continue to develop it because even in it current shape it's the most useful shader I currently use.

@FierySwordswoman hey i was wondering, based on your experience with editing LUTs in Gimp... do you find that the "preserve luminosity" feature in the "color balance" section translates well to the in-game final result? Or do you suggest leaving that box empty?

@robgrab i completely agree with you. It's without a doubt the most important shader to me as of a few weeks ago. The level of granular control it gives you is so ridiculously powerful, it opens up so many doors of possibilities and creativity.

@MartyMcfly Even though you're ostensibly unhappy about it being leaked/public, i still wanna say thanks for creating it in the first place. Not that you owe any answers but i'm curious, why did you abandon it? Or are you just not satisfied with it in it's current state?

SandyCheeks wrote: @FierySwordswoman hey i was wondering, based on your experience with editing LUTs in Gimp... do you find that the "preserve luminosity" feature in the "color balance" section translates well to the in-game final result? Or do you suggest leaving that box empty?

stuff about lightroom shader

Depends on the effect you're trying to achieve, honestly. Just toggle it on/off and see what looks better.
I prefer Curves over the color sliders. Easier to white balance with.

Side note,, why bother using the Lightroom shader if you're going through GIMP anyway?

is there anyway to convert lightroom value to photoshop ? like global contrast 1.2 what would it be in photoshop...

Can have implements depth buffer in Lut ?? one Lut for scenario and another with Depth for background ??
I think using depth in luts can make more color change

Chavolatra wrote: Can have implements depth buffer in Lut ?? one Lut for scenario and another with Depth for background ??
I think using depth in luts can make more color change

it's possible, but that shader currently doesn't exist.

@FierySwordswoman Thanks for the response, I've tried on vs off and i have my own opinions on the results. I was just asking what your opinion is since you were actually the person who introduced me to using LUTs via reshade in the first place (so i respect your opinion on the subject).

To answer your question... I don't use them both, i used LUTs previously but after being introduced to the lightroom shader I've personally gotten much better results there. I find it allows for much more fine-tuned tweaking, as well as the benefit of seeing how the edits react to various angles/TOD of the game in real-time.

One simple question regarding this:
As far as I understand from reading the OP and some of the following posts it’s just a different approach opposed to using the shaders included as standard like ToneMap, Vibrance, Technicolor (or any others which shift colors for that matter, but those I found to be the ones which give me good results).

Is that correct? What are the (dis)advantages of each approach?

You combine multiple shaders with lots of calculations into a single texture lookup, which most of the time is faster. So a LUT generally gives you better performance. And it is easier to manage if you already have GIMP/Photoshop skills, compared to adjusting the settings of all the other color shaders to match.

so if i only use tonemap for color correction am i no longer need LUT ? or LUT still can give me faster performance & better color correction quality ?

From my experience LUT performance was better, and quality was okish, slightly lower maybe but i don't measure it, naked eye exam only.

Would there also be a convenient way to get the same result, as I have now with a combination of ToneMap, Technicolor, Vibrance and DPX? (without a lot of fiddling in gimp, since I would have no idea what I’m doing anyway ^^)? Meaning some kind of a „translator“ or if that’s not possible – as Im suspecting – at least a way to determine what values to change in gimp?

SurfNSlide wrote: Would there also be a convenient way to get the same result, as I have now with a combination of ToneMap, Technicolor, Vibrance and DPX? (without a lot of fiddling in gimp, since I would have no idea what I’m doing anyway ^^)?

often shader presets you can find are redundant, meaning they will use different shaders to accomplish the same thing or overwrite what another shader is doing, just to accomplish what looks like a good balance ON THEIR SCREEN (with their own colors, brightness, etc)... every shader has its own pro and cons but usually the best it's to avoid redundant changes.

a LUT image is good for colors and tonemapping, but if you don't know how to change an image (but it's pretty easy to learn as you have limits on what you can change on a LUT) just fiddle with shaders ingame. i would say you can probably delete Vibrance and enanhance the colors just with DPX and technicolor (or tonemap too) as a start.

Not trying to be a turd here (and I has a question about the LUTs, see bottom), but I think referring to this process as "color correction" is VERY misleading, as this will not be "correcting" anything. This is color mapping. There is a lot of misinformation out there when it comes to this kind of subject. I mean in general, like the "warm" color temperature option on some displays as being "too red!" when they're actually looking at something that's too blue (I've seen some people use this as "proof" that some ISF certified calibrators are a scam and don't know how to do their job... *facepalm*)

To keep it simple, every person's eyes see light differently, and every display will show light differently. You can draw an orange (255/128/64) line, but what your display is REALLY sending to your eyes is NOT really that if you were to measure it with equipment.
It could be really close, or not (looking more like a brown). Color "correction" takes that orange and remaps it to something so your display will actually send that orange to your eyes.
ex: Your display after all of it's processing (brightness/contrast/etc) and shows that orange as 235/111/80. To make it actually show as 255/128/64, you need to remap this rgb triplet to 235/135/30 (brightness/contrast/light/etc), and to correct it a LUT needs to remap it to 235/135/30 for the display to show as intended (255/128/64). These numbers are just to illustrate the point.

I hope I don't come across as if I am standing on a soap box. There is absolutely nothing wrong or anything bad about doing this color mapping. Just that it's not "correction" lol.


BTW, If you're wanting real color correction via LUT, you can use something like DisplayCal (free) to profile your display and generate a 3D LUT for reshade. But you'll need measuring equipment for this.
You can also use this to do other things without equipment ala synthetic profiles and 3D LUT Maker, like...
Change color spaces & display technology (make a simulated LCD look like a simulated CRT/camera/projector.). Helps get that retro feel for arcade cabinets
Do gamut shifts to help various types of color blindness without effecting the rest of the colors.
Custom gamma curve without touching in game or display controls (game controls are usually mislabled or poorly implemented, but I have my own equipment so no clue how well this works).


I remember reading a few years ago about reshade not supporting external textures with more than 8-bit depth. Since HDR is becoming more popular in the PC world, and is already standardized to have 10-bit depth, does reshade still have this texture restriction (I think it would need 16-bit textures for HDR 3D LUTs?)
All I use it for is 3D LUT color correction so I haven't followed it's development at all.



Also, random thought before hitting submit.
Is anyone familiar with Darbee Darblets (or have an OPPO player that has one)? They have a really neat effect and I'm curious if it could be replicated via reshade.
Seeing it in person is a whole different thing than seeing screenshots or videos of it. It's one of those "see it to believe it" things.
www.darbeevision.com/images/

Actually, a LUT is simply a look-up table. It simply translates one set of values into another.

In this context, LUTs are being used for correction or grading. What you're describing is display calibration which is different still.

Correction is just the practice of correcting white-balance, exposure, and setting proper contrast.
Grading is when you stylize the image.
Calibration is where you correct a monitor's output.

LUTs are often used in the practice of all three scenarios.

I apologize if I am a bit late to the party.

Is there any way we could find a video tutorial? ive been tyring to do this for over 3 hoiurs and I cant seem to be able to figure it out. There is a single youtube tutorial, but it doesnt use the software you are using. Is there an updated guide as of 2018?

Thanks again

For the foreseeable future, I will not be updating this guide. Details:


If an admin sees this, you can probably just copy-paste the above to the top of the OP so people understand that this thread is effectively dead. I still can't edit it due to the amount of image links.

TreyM wrote: Actually, a LUT is simply a look-up table. It simply translates one set of values into another.

In this context, LUTs are being used for correction or grading. What you're describing is display calibration which is different still.

Correction is just the practice of correcting white-balance, exposure, and setting proper contrast.
Grading is when you stylize the image.
Calibration is where you correct a monitor's output.

LUTs are often used in the practice of all three scenarios.

Erm, no, not exactly. Back in the day, before madVR, before ReShade LUT profiling, there were 3DLUT boxes, actual hardware boxes costing $500+. They had to be calibrated using expensive software like CalMAN and they did exactly what ReShade LUT.fx does today, but 3DLUT boxes did it on hardware level, while LUT.fx 3DLUT's do it on software level.

With LUT.fx you can correct both parts:
1. Grayscale (luminance, gamma, RGB balance, temperature)
and
2. Colorspace / color gamut (hue, saturation, etc.)

LUT.fx is more applicable than ICC profiles in games because ICC profiles can only enforce "vcgt" / grayscale / 1DLUT portion of their data into Direct3D/OpenGL/Vulkan environments. They sometimes even fail to do that, often requiring a 3rd party "vcgt"-enforcing application like CPKeeper and/or the use of Borderless Window mode.

ICC profiles can apply both grayscale and colorsapce / color gamut only to environments that fully support them, such as GIMP or Photoshop or some other editing software.

I don't like to play games without LUT.fx... So far Wolfenstein II was the only Vulkan-only game and required me to use CPKeeper running to enforce the only corrections I could - from an ICC profile.. Few games don't support ReShade. Even Metal Gear Solid - Phantom Pain supports 1 version (one of the earliest ones) of ReShade with LUT.fx support... The thankfully-slow, but unfortunately-steady rise of DirectX 12 and Vulkan is why I beg Crosire to submit to desires of the masses and develop both DirectX 12 and Vulkan versions of ReShade...

There are cases when monitors with excellent image quality (due to high contrast ratio, black levels, etc.) do have poor color accuracy. Yes, excellent image quality with poor color accuracy is very possible, especially on VA panels like Eizo Foris FG2421. With just ICC profile, 1DLUT, that monitor produced immersive image, but skin tones, skies, and grass were all using inaccurate hue's, but with LUT.fx / 3DLUT, the resulting image was almost entirely corrected, except for the most saturated reds, which remained a bit pink. Check out the difference between 1DLUT (top) and LUT.fx 3DLUT (bottom):
drive.google.com/file/d/15zy6RDqBQSHN0kQ...-VW/view?usp=sharing
drive.google.com/file/d/1cbdw5QuFK5hlmrk...z-e/view?usp=sharing

The actual dE error values with LUT.fx 3DLUIT's were much better than these graphics demonstrate. Everything was within dE of 1, except for the most saturated reds and blues.

LUT.fx 3DLUT as a method calibrating one's display is very real and very practical. It's generated specifically for supporting environments, such as madVR (film playback renderer) and ReShade via DisplayCAL, a powerful GUI based on ArgyllCMS, color engine, one created by one of the most knowledgeable color scientists and an expert in his field. My LUT.fx file size is about 700KB. I don't remember which profile settings I picked, but I think it included measuring and correcting over 10000 points.

I tired this a few years ago. Doing the LUTs at 4k res, it made the in-game image red and black. What would be the cause of that as I'm afraid to try again.