what is Gamma Correction

24

Comments

  • Mustakettu85Mustakettu85 Posts: 2,813
    edited December 1969

    you talking about this package?
    http://www.daz3d.com/multi-layered-image-editor
    I don't have that.

    Also...
    if you use the “Render to a new window” mode, you will need to do the “save file - correct - view” routine
    is that one of the buttons on this Render (1/1)window?

    MLIE has been included in DS4 Pro since the beginning. I do not have DS installed on this particular computer, so I cannot post a screenshot, but it is in the same dropdown menu as "simply" Image Editor etc, next to each and every texture in the "Surfaces" pane.

    I am sorry that I am about to ask a personal question, but would you mind disclosing how long ago you have started using DS? And what technical background do you have, i.e. are you coming from another software package, how familiar you are with computer graphics in general etc? It will probably help everyone gauge the detail level of the advice we are giving to you.

    As for the render window... I am sorry I do not really understand what you mean. There is certainly a "save" button. Other than that, you will need an image editor (separately obtained piece of software like GIMP) to perform post-render gamma correction. So you would use the "save" button to save the file, then open it in an image editor.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited December 1969

    I think I follow you now. Gamma setting #.## only works if I save directly to a file. I prefer the window as I can tell rather quickly if it is going to be good or not, rather then waiting an hour for junk, lol. I should stop that habit of watching the final draft render, as I read my physics books.

    Background;
    It has been a few years since I was involved with anything graphics remotely like this (mostly GPU hardware as an offshoot of a particular RISC CPU tech). Lets just say I use to know a thing or two about a particular "Unix-like operating system" memory manager, and a particular ALU from a very long time ago.

    I dabbled a bit with Op-Amp glass, before joining the NAVY as an Electrician. About the time I 'retired' from the NAVY, I was fascinated with Game graphics technology threw the GeForce FX line and on. I didn't build any thing by then, I just read anything I could find about the GPU tech.

    Then I got distracted from the computer industry the past five years (about). Rocks, Music, and Amateur Radio.
    I am here for to have fun, as I know nothing about "Hollywood CG".

    Pixar used the Mandelbrot set, to create some realistic looking mountains back in the day, I don't know how. Marcus du Sautoy didn't go that far into it, and Daz Studio is much more affordable.

  • kitakoredazkitakoredaz Posts: 3,526
    edited December 1969

    Hi,,Mustakettu :)

    I have two question which I have hoped to ask someone about DS gamma correction.:red:
    how do you think about "Specular Color map and Opacity strenght map" of ds shaders?

    Usually DS auto Corerct Gamma about specular map too.

    my experience, when I change specular map to "1.0" I can get more reliable specular efefct,,
    with gamma correction on. but Can I treat it as controll map?
    or it only need when the texture is used as specular strength map?

    and about opacity strength , ds keep linea "1.0", I think it is right.
    but if I set inverse color map as opacity strength as filter,,to make gel light ,
    may I need to change gamma as " 0 (2.2)" ?

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited December 1969

    Specular Strength I think it was called. I used that in combination with the reflection strength as a mask for spots I don't want to reflect. Haven't done much else with that. yet.

    I installed Daz Studio for the first time around 2014-03-29. Befor that, it was just diagrams and schematics in Ms Paint, and PhotoDeluxe.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited June 2014

    It's funny, the reflection strength image spot is only for pictures to fake a reflection, not a mask for real reflections.

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  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited June 2014

    Opacity strength map” of ds shaders?

    That I have used for clothes to make a shear cloth effect, and others do as well. not all clothing has user-texture friendly polygons tho.

    If I remember correctly, White is opaque, and black is essentially not there, with the gray scale in between. I'm sure that is linear threw and threw, so no gamma adjustment, I guess.

    Post edited by ZarconDeeGrissom on
  • RuphussRuphuss Posts: 2,563
    edited December 1969

    why all the math when you have eyes to see ?
    just turn it on or off and look at the results
    that's all what counts

  • SertorialSertorial Posts: 962
    edited June 2014

    ruphuss said:
    why all the math when you have eyes to see ?
    just turn it on or off and look at the results
    that's all what counts

    from what I can see above, it should be switched on and gamma should be set to 2.2

    Is it something to do with the texture maps (say in the diffuse channel) being "fixed" before they go into a render so they match the screen properly (that's about as much as I can understand from the above!). I understand the inverse square law (as I am a scientist by training) and I am perfectly fine with the mathematics of gamma being an index.

    What I don't understand is what this is being applied to? Someone said it was not to correct the gamma of your render, but to correct the maps going into the render. Is that it?

    Oh, and one last thing. Someone said above about setting your gamma value independently of the gamma correction switch. But if gamma correction is switched off, surely the gamma value will have no effect? Isn't this just the value the gamma correction uses? (therefore is it's switched off, the gamma value is irrelevant?)

    Post edited by Sertorial on
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited December 1969

    That is confusing how the mashed thew's two adjustments together. "Gamma correction" is for the input of the render engine, Diffuse map I think, get adjusted if they need it according to some "magic function".

    "Gamma" slider, and please allow me to throw a wrench in this... "Gain"???
    This is applied to the render results, regardless of the other settings. like the brightness/contrast vs the "temperature" settings in a monitor.

    2.2 vs 1.0 vs 0.45 ???

  • Richard HaseltineRichard Haseltine Posts: 70,725
    edited December 1969

    The Reflection Strength map controls strength, the reflection colour (on the default shaders) replaces true ray-traced reflections with mapped reflections.

    Images will generally need correction when they are made by eye, looking at images on a monitor to gauge the colour, as those adjustments will have been made at gamma 2.2 (or whatever the monitor was set to). The gamma correction pulls those back to gamma 1.0 for use in 3Delight.

    The Gamma Correction button controls whether DS corrects maps before feeding them to 3Delight - 3Delight itself will apply the Gamma value to its output. Since one controls something DS does in preparing the images for rendering and the other controls something the renderer does they can be set independently - you might conceivably be using images that don't need correction, and simply turn Gamma Correction off rather than editing each image to have a gamma value of 1, while still wanting a final gamma correction on your render.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited June 2014

    ruphuss said:
    why all the math when you have eyes to see ?
    just turn it on or off and look at the results
    that's all what counts

    The argument persists, so it is time to take some measurements, and see if they match the theory. Way back when I first started using daz studio, I was asking what all these sliders actually do in the render tab. I was told then, probably as I was yet to make a render of anything, leave it all default. Mess with the shadow Samples for grainy shadows, and sample rate for the finer details vs render time.

    I monkeyed around a little more then that, and gamma other then 1.0 with or without Correction On, just didn't look correct. I was less then a month into CG and had no clue tho.

    I Just put it back to default, until I had a clue, I still don't. lol
    (edit)
    Cool pic, lol. yep, the 2.2 looks about correct.

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    Post edited by ZarconDeeGrissom on
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited December 1969

    If you don't mind using the buttons on you monitor, here is another cool site.
    http://www.lagom.nl/lcd-test/

    I'm not fond of using software to calibrate external analog hardware, tho that is a preference.
    That potentiometer is there for a reason, lol.

    LCD/IPS/etc flat panels, especially with a DVI connection, it just doesn't matter. if you use the monitor controls (Assuming it is a good one), or the graphics chip in the computer.

  • SertorialSertorial Posts: 962
    edited December 1969


    Images will generally need correction when they are made by eye, looking at images on a monitor to gauge the colour, as those adjustments will have been made at gamma 2.2 (or whatever the monitor was set to). The gamma correction pulls those back to gamma 1.0 for use in 3Delight.

    The Gamma Correction button controls whether DS corrects maps before feeding them to 3Delight - 3Delight itself will apply the Gamma value to its output. Since one controls something DS does in preparing the images for rendering and the other controls something the renderer does they can be set independently - you might conceivably be using images that don't need correction, and simply turn Gamma Correction off rather than editing each image to have a gamma value of 1, while still wanting a final gamma correction on your render.

    Thanks for this Richard. I think I understand now. Here are some test renders of Genesis2 right out of the box with a simple two-light setup. I think it shows that correction on and gamma at 2.2 is about the best result of the four.

    So I have two questions..

    1) the gamma correction fixes maps which were created on a dodgy monitor. But what if the maps were properly corrected in the first place? Presumably gamma correcting them again spoils them?

    2) the gamma setting control needs to be set to match the monitor you are rendering on, yes? So since most monitors are set at 2.2 this is the right value to use?

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  • prixatprixat Posts: 1,264
    edited June 2014

    Sertorial said:
    1) the gamma correction fixes maps which were created on a dodgy monitor. But what if the maps were properly corrected in the first place? Presumably gamma correcting them again spoils them?

    Think of 'Correction' as a mathematical term. Its not fixing something that's broken, its returning it to it's original state.

    Take Zarcon's photo of a Rock.
    A spot on the rock is recorded on the sensor at 99% brightness.

    When the camera saves it as jpeg it obviously uses the sRGB standard (gamma 2.2 is part of the standard.)

    That adjusts the brightness, steps it down and 99% is saved as 90%.

    It does adjustments to all brightness levels by different amounts depending on the curve. (for example, 50% at the sensor will be 46% in the jpg, our eyes don't need any help with darker colours so 1% at the sensor is 1% in the jpg)

    The brightness is quite literally graded on a curve! (There's actually more than 1 curve because our eyes respond to each colour differently.)

    3Delight can get back to those original values and (assuming it was done to the standard) the de-gamma 'Correction' can be done with no losses or changing anything to a log scale. :)

    (there certainly are badly made jpgs from wildly uncalibrated monitors but that's a relatively easy fix in photoshop)

    Post edited by prixat on
  • RuphussRuphuss Posts: 2,563
    edited June 2014

    @sertorial

    "I think it shows that correction on and gamma at 2.2 is about the best result of the four."

    can you explain why you think this pls ?

    Post edited by Ruphuss on
  • SertorialSertorial Posts: 962
    edited June 2014

    prixat said:
    Sertorial said:
    1) the gamma correction fixes maps which were created on a dodgy monitor. But what if the maps were properly corrected in the first place? Presumably gamma correcting them again spoils them?

    Think of 'Correction' as a mathematical term. Its not fixing something that's broken, its returning it to it's original state.

    Take Zarcon's photo of a Rock.
    A spot on the rock is recorded on the sensor at 99% brightness.

    When the camera saves it as jpeg it obviously uses the sRGB standard (gamma 2.2 is part of the standard.)

    That adjusts the brightness, steps it down and 99% is saved as 90%.

    It does adjustments to all brightness levels by different amounts depending on the curve. (for example, 50% at the sensor will be 46% in the jpg, our eyes don't need any help with darker colours so 1% at the sensor is 1% in the jpg)

    The brightness is quite literally graded on a curve! (There's actually more than 1 curve because our eyes respond to each colour differently.)

    3Delight can get back to those original values and (assuming it was done to the standard) the de-gamma 'Correction' can be done with no losses or changing anything to a log scale. :)

    (there certainly are badly made jpgs from wildly uncalibrated monitors but that's a relatively easy fix in photoshop)

    I am not sure you have answered my question 1) - if DAZ Studio gamma corrects maps that are already correct, won't it spoil them? (analogy - if something is the wrong way up and I invert it, it is now the right way up. But if it started out the right way up and I invert it, it is now the wrong way up - see what I mea?) Or are you saying if the maps are already correct, then another gamma correction will leave them unchanged? (keep it very simple please!). I am really not a technical person

    Post edited by Sertorial on
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited December 1969

    Out of idle curiosity, what 'Type' of lights did you use? Menu spot lights, DzLights, Uber Lights, etc?

    The results I got were not the same to put it lightly. I just got back, and am in the process or replacing almost all the lights (except the Uber beam thing).

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  • prixatprixat Posts: 1,264
    edited December 1969

    Sertorial said:
    analogy - if something is the wrong way up and I invert it, it is now the right way up. But if it started out the right way up and I invert it, it is now the wrong way up - see what I mea?

    The analogy of school exam results is a bit closer.
    The school applies grades to the results but to get some meaningful numbers you have to 'Correct' the grades back to the actual results.

    In my example Zarcon's camera 'graded' the brightness values but 3Delight only works accurately with the actual brightness values.

    I don't think anyone has explicitly gone into why the standard includes this 'grading' because that's all about human biology.

    You're right, if Zarcon takes it into photoshop and does the 'de-gamma' Correction there you don't have to do it again in studio. That's how we did things before Linear Workflow got written into software.

  • SertorialSertorial Posts: 962
    edited June 2014

    Out of idle curiosity, what 'Type' of lights did you use? Menu spot lights, DzLights, Uber Lights, etc?

    .

    Just a couple of distant lights with shadows on. One to the left at 100% (key) and the other to the right at 20% (fill)

    prixat said:
    analogy - if something is the wrong way up and I invert it, it is now the right way up. But if it started out the right way up and I invert it, it is now the wrong way up - see what I mea?

    The analogy of school exam results is a bit closer.
    The school applies grades to the results but to get some meaningful numbers you have to 'Correct' the grades back to the actual results.

    Thanks, but I am still not clear about my question. Is there any harm in having gamma correction on? I mean if the maps are correct to start with, will another gamma correction spoil them, or leave them unchanged. Since you have made the analogy of the school exam, correcting the marks twice will spoil them, right?

    What i am asking is this: gamma correction fixes a map that was wrong to start with. But what if the map was right to start with? I have gamma correction switched on by default as I don't know which maps are already gamma-corrected. I don't know how to explain myself better than this!

    Post edited by Sertorial on
  • kitakoredazkitakoredaz Posts: 3,526
    edited June 2014

    Setorial I understand where you feel difficulity.
    Then, I think it is (edit %-P) not important how the textures are made about color map.
    (eg diffuse color map, ambient color map, subsurface color map etc)
    and do not worry, if the texture gamma are already changed or not.
    (though texture vendor may worry, what setting we use for our monitor,and may hope keep default)

    Because when apply texture for shader property,
    I have seen each texture color in my monitor with the monitor gamma setting.
    then select , apply or modify each texture.
    (we suppose the texture color should be calcurated correctly when we render)

    If my monitor setting is default Gamma (2.2), then see texture which made by another setting gamma,
    I may think, the texture (which made another Gamma) is too dark. or too bright.

    after all, I may select and choose only texture which I feel it is good with our monitor and gamma setting.(2.2 about my case)
    or modify RGB in shader property or image editor, then apply these textures.

    when render with Gamma Correction On (gamma 2.2 default monitor setting of me) in DS,
    the rendered pic should show correctly circulated texture color adjusted by DS about color map
    (but it is color which I have seen in my monitor").

    You may only need to check current texture color in your monitor with the monitor gamma setting (2.2).
    then adjust it for your monitor. after that DS correct textures gamma when you render.

    Post edited by kitakoredaz on
  • Richard HaseltineRichard Haseltine Posts: 70,725
    edited December 1969

    If a map doesn't need correction then you find it in the Surfaces pane (any isntance of it will do if it's used on multiple surfaces), click the preview square to get the menu, select Image editor and set the value to 1.0. You certainly don't want gamma correction applied to iamges that don't need it as they will then end up much too dark.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited June 2014

    I kind of passed out at the keyboard last night, sorry.

    If a map doesn't need correction then you find it in the Surfaces pane (any instance of it will do if it's used on multiple surfaces), click the preview square to get the menu, select Image editor and set the value to 1.0. You certainly don't want gamma correction applied to images that don't need it as they will then end up much too dark.

    Ok so in simpler terms. If you have Gamma Correction ON, and a texture somewhere in your scene is mislabeled by the creator... Then the (Gamma Correction Inter-stage, whatever) will just blindly apply the gamma adjustment it thinks it needs based on the bad data in.

    IF ALL the textures in your scene are labeled correctly (regardless of base Gamma they are), Gamma Correction ON will do no harm. It will only flip over the chairs that are upside down, and leave the others alone... IF ALL the textures in your scene are Gamma-labeled correctly.

    Otherwise, it will flip the chairs it is "Told" are upside down, even if there correct to start with.

    P.S
    I removed the simple "Menu" lights, and am about to try the "DzLights". As for key and fill's, I kind of thought that if the fill and key illuminated the same side of a something, they should add up roughly to 100 (100% + 10%, obviously is close enough). Apparently I was wrong there, and the percent is relative to a ### watt bulb of sorts.

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  • kitakoredazkitakoredaz Posts: 3,526
    edited December 1969

    As for me, the difficulity is, about some non color map, I can not clear, the gamma correction need or not.to see
    default effect which vendor desigend.

    (it is not about good or bad, simply to use the original effect which desigend by vendor at start point)

    so that I like these type product

    http://www.daz3d.com/photo-studio-kit

    it clear discribed in read me,
    The materials and lights presets are meant to be used gamma correction enabled and with a Gain of 1 and Gamma of 2.2

    I believe most of color map need to correct gamma for render, ( in image editor gamma 0.0 )
    to get reasonable effect.
    .
    because most of them are made in vendor monitor with 2.2 gamma ,then they will offer them
    without tweak gamma.

    If vendor corrected color map gamma already for 3d render.
    it just make user difficult when check the color of texture, and suppose how they work when render..

  • Richard HaseltineRichard Haseltine Posts: 70,725
    edited December 1969

    Gamma 0.0 in the Image editor is telling Ds to guess the right value based on context - any non-zero value is telling DS to use that as the image's gamma.

  • kitakoredazkitakoredaz Posts: 3,526
    edited June 2014

    I hope to know What context base? ^^;

    I have seen many document about gamma correction, yes I understand how it work and why it need,
    But important thing is most of aprication which offer gamma correction utility,
    must show clear document.

    They tell me, how use gamma setting for each property, and tell me exceptional case.

    but about DS where I can find the Context base? (not say to richard, but I feel strange why DS still not
    offer clear document about gamma correction and in image editor gamma)

    IF I can see what context ds shaders use for maps applied each property of shader,
    or even though I can not understand the context, I only need, which texture need gamma correciton or not.

    And I think, DS still often miss read the context about some controll maps of some shader, then change gamma of them too.
    If I can believe the Context base perfeclty, I may need not change gamma to 1.0 in image editor about some map.

    Post edited by kitakoredaz on
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited June 2014

    Now for the baffling question for me, and that gamma preset thing.

    I'm selecting a cooler value in that numbers-box thing for the primitive, with NO map at all.
    The Red, Green Blue spheres, the floor (Just a displacement map), and the walls.

    What am I supposed to do with them, to make sure Gama Correct, knows that 128 is indeed mid-gray, and 255 (the spheres) is the max value?

    Post edited by ZarconDeeGrissom on
  • Mustakettu85Mustakettu85 Posts: 2,813
    edited December 1969

    Hi everyone,

    Folks, your confusion totally mirrors the confusion I used to be in. Almost word for word. So don't worry, it will all sink in, get digested and leave you with that "OMG now I really get it" feeling some day soon =)

    How to tell if the diffuse map is not pre-degamma'ed:

    - open it in an image viewer (something simple like IrfanView without any colour management enabled). If it looks about as bright as the actual RL material it's supposed to represent - then it is in gamma space and you can safely linearise it. If it's a lot darker - then someone took care to linearise it by hand...

    But I have never ever seen any DS/Poser product or freebie have pre-linearised colour maps (and I've seen quite a few =)))

    -----


    my experience, when I change specular map to "1.0" I can get more reliable specular efefct,,
    with gamma correction on. but Can I treat it as controll map?
    or it only need when the texture is used as specular strength map?

    and about opacity strength , ds keep linea "1.0", I think it is right.
    but if I set inverse color map as opacity strength as filter,,to make gel light ,
    may I need to change gamma as " 0 (2.2)" ?


    Hi!
    You see, it depends on your type of specular map. Is it grayscale or does it have colour? If it is grayscale, it works like a strength map aka control map. So technically, it does not matter whether if it's in the colour or strength channel - because colour and strength will be multiplied in the shader.

    The "good style" is, of course, to stick this control map in the strength channel (so as not to confuse yourself and anyone else).

    BUT - what I am leading to - it should be treated as linear, of course. Gamma "1". Regardless of where you stick it.

    And if your specular map has colour varying over the surface - then it is a colour map, should only go into colour to work at all, and hence it should be de-gamma'ed to "0" (which would be more like roughly 0.45, if you were to apply it in an image editor by hand, of course; this is why I am putting inv.commas around that zero all the time).

    As for coloured transparency in a gel light, this is an interesting question. I'd say it should be at "0" to give predictable results colour-wise. A light is not really opaque by itself, it only has colour.

    ----

    ...
    I am here for to have fun, as I know nothing about "Hollywood CG".

    Thank you Zarcon for replying... I will take care to be more specific as to where some things are in DS, then.
    And the good thing about DS is that we have the same render engine as some of the Hollywood CG guys! =)

    I think I follow you now. Gamma setting #.## only works if I save directly to a file.

    Well not exactly. Its effect WILL show in the Render window that DS displays (DS, it may be different with the standalone 3Delight because of colour management in i-display... but you are not rendering with the standalone, are you?).

    But if you enable GC yet leave gamma at 1, you will not see the "monitor match" effect right away, but you can later get the same effect by gamma-correcting the saved render.

    As for Gain: think of it as the camera's exposure. Higher "gain" - longer exposure - more light onto the film - lighter everything. An artistic control, generally speaking. If you routinely overlight, you may set it a bit lower, like 0.9; and the other way around, those who tend to underlight may like it set a bit higher.


    What am I supposed to do with them, to make sure Gama Correct, knows that 128 is indeed mid-gray, and 255 (the spheres) is the max value?

    Now that is indeed interesting - does turning GC on in DS also apply the curve on colour pickers? I know there used to be issues with that even in some big name software packages.

    But to tell the truth, I never really bothered to test. The way we render in DS, most of the time we are using texture maps for our colours, not procedural shaders, so the most important input for the correct look is the linearised colour map. All the other colours are mostly limited to "tinting" and have always been added mostly by "eyeballing", so in this sense, it does not really matter if the colour picker is gamma-corrected. You just tweak till you like the look.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,399
    edited June 2014

    Another interesting twist, lol.

    Mec4D said:
    There is a difference between gammas and I see Szark getting really confused :) lol
    If you create art on your computer your monitor need to be calibrated to match the printing as much as possible
    you can do that manually using windows calibration or use a special device . Most of the monitors are NOT 2.20 but simple 1.00
    to have a 2.20 gamma your monitor would have a wide gamma and it is expensive one .

    The gamma correction in Daz Studio is a compressor that correct the curve of the image for the best result .
    if you use Gamma correction ON , your gamma should be set on 2.0 ( for the wide range )
    if not the gamma should be set on 1.00 so the correction can be done for example in Photoshop

    Usually the Gamma correction suppress the highlight preventing it from ( burning the colors - over-exposure ) as it is in photography
    mostly all color textures are shot with gamma 1.0 and the Gamma correction ON in DS with the Gamma set on 2.0 will prevent it from overexposure especially if you use to much light in the scene

    for example if you use UE2 with base light and add one more distance or spot light the image would be automatic over exposed as the power of the light will end in double , since 100% value of light usually is 1000 Wat so you ending with 2000 W straight in the face what call for Gamma correction ! or reducing in power light ..
    thanks to Gamma correction ON and Gamma 2.0 the render will be compressed and overexpose reduced ending with a brilliant color and balance
    (snip)

    so each light at 100% is equivalent to 1kW? or was that an arbitrary number for the sake of understanding the concept (Using Gama Correction to counter two much light in the scene)?

    (edit)
    We doubled.
    I'm using whatever 3Delight came with DS 4.6.3.52 ("O", it updated from 50).

    Post edited by ZarconDeeGrissom on
  • SzarkSzark Posts: 10,633
    edited December 1969

    so each light at 100% is equivalent to 1kW? or was that an arbitrary number

    yes no one really know how bright 100% is. Well I asked a while back and the consensus seemed like know one knew. ;)
  • Mustakettu85Mustakettu85 Posts: 2,813
    edited December 1969

    PS


    And I think, DS still often miss read the context about some controll maps of some shader, then change gamma of them too.
    If I can believe the Context base perfeclty, I may need not change gamma to 1.0 in image editor about some map.

    That's a correct observation. It is necessary to set a bump or a specular map to the "1" value, otherwise it will get treated as if it has to be linearised.

    I'm also not sure if DS saves the correction values into material presets. I believe it does save them with the scenes, but material presets? I saved this - http://www.sharecg.com/v/76578/view/21/DAZ-Studio/SSS-Tutorial-companion-preset-for-example-4 - from a scene that saves, opens and renders consistently. When I applied this preset to a new figure to test, I found out that at least on my particular machine the spec and bump got set to "0" and so rendered differently. So I had to write that lengthy warning... which is okay for a random tiny freebie, but what if I wanted to sell a set of materials optimised for linear workflow?

    Apparently there either is a currently minor but potentially devastating issue, or there is something I overlooked and there is a way to make sure the correction settings get saved properly. Help?

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