Quote - > Quote - Pardon the stupid question, but is it a hard and fast rule that GC has to be set at 2.2 if you're using a PC?

Only if you need it for you monitor. I never heard it was a rule as that would f**kup my images.

I'm referring to the GC settings in Poser, not my monitor.
Both my monitors are calibrated.

Quote - Pardon the stupid question, but is it a hard and fast rule that GC has to be set at 2.2 if you're using a PC?
Couldn't it be set at 1.2 or 1.3 if less of the effect were desired?

Good question actually.  There's no hard and fast rule that GC has to be set at 2.2 if you're using Windows.  We use the gamma values of 2.2 for Windows and 1.8 for MacIntosh because that's what most monitors have.  I don't see why you can't experiment with other gamma values.
 

just a quick note to say cspear - that's not quite how it works.  Poser 8 does not do anything to your image.  the image itself is sRGB, because it is a digital image in that color space.  and all monitors are sRGB.  not all have specific defined sRGB space calibration, like, say, Adobe sRGB, but they're all sRGB.  there are no linear color space monitors.  and afaik,  there are no sRGB space renderers.  optics is hard enough with linear calculations, and it's much easier to just transform the result.

Wikipedia

Quote - LCDs, digital cameras, printers, and scanners all follow the sRGB standard. Devices which do not naturally follow sRGB (as was the case for older CRT monitors) include compensating circuitry or software so that, in the end, they also obey this standard. For this reason, one can generally assume, in the absence of embedded profiles or any other information, that any 8-bit-per-channel image file or any 8-bit-per-channel image API or device interface can be treated as being in the sRGB color space.

Quote - > Quote - Pardon the stupid question, but is it a hard and fast rule that GC has to be set at 2.2 if you're using a PC?

Couldn't it be set at 1.2 or 1.3 if less of the effect were desired?

Good question actually.  There's no hard and fast rule that GC has to be set at 2.2 if you're using Windows.  We use the gamma values of 2.2 for Windows and 1.8 for MacIntosh because that's what most monitors have.  I don't see why you can't experiment with other gamma values.
 

Here's why.

Quote - Thanks for the feedback Zaycrow.  I will further reduce the intensity of the IBL light and crank up the spotlight just a bit to see if we can get the GC'd image to look more 3D.  What kind of monitor is your old monitor?  And your new one? (if you wouldn't mind)
 

Well, that's the problem -  if you crank up the CG my new monitor will show it as too much gamma control. My old monitor see it ok, but that's the problem with LCD's. At work we still use CRT screens and those old things still show the CG images here as too much gamma corrections.
My old monitor is a LG 19". My new monitors are Phillips Brilliance 20" 200W and Samsung 30" 305T plus.

hawarren: ty for the link - exceptional quality work- yes I like

Quote - There's that "see" again.
Mathematically correct is not something that can be visually assessed.

I always wondered why the first question that's usually asked of people looking for help in improving their renders in this forum was "Did you GC it?"

I always wondered, if you can't tell and have to ask, how can it possibly matter?

If it matters to you, great.
But I guarantee that almost every single person who posts a render here or in the critique forum asking for help wants to improve the appearance of that render.

I have yet to see anything here entitled "Please help me make my render more mathematically correct."

Possibly some of those who post in threads containing renders of figures floating in space in T-pose are wanting that sort of correction. Good for them.

But I've yet to be paid for getting a naked figure in t-pose mathematically correct.

So I guess I should rephrase my original question: "What's the big deal with gamma correction in the context of how my final render will appear?"

Quote - So I guess I should rephrase my original question: "What's the big deal with gamma correction in the context of how my final render will appear?"

There are a number of factors to consider when creating a good image.

Colour processing is one such factor. It is the base factor, really. Poser uses linear colour information to process colours. If you want to Poser to process the colour correctly, then give it linear data.
Lighting is tied in with that.

I'm not sure how else to say it.

All the clever rhetoric about how everyone's monitor is calibrated differently and how great images were produced prior to knowing about Poser's need for linear data is irrelevant to that fact. Granted that the information might have been more gently presented, but one cannot discount the fact that Poser uses linear data to process colours.

Do with that information what you will. I'm not saying anything about whether your image quality will suffer from not using GC... I'm merely stating a bald fact: Poser uses linear data to process colours.

Quote - If you want to Poser to process the colour correctly, then give it linear data.

But why should I care whether the colour is processed correctly?

If it appears correct, what has its actual correctness got to do with anything?

We have people using lights without shadows. How does that fit into correctness? It doesn't. It's an attempt to give the appearance of correctness.

We have figures with gross anatomical flaws and faulty joints. We have skins and flesh that doesn't react to surface collision with other objects. We have muscles that don't flex when we change figure poses. Spines with 2 joints. And let's not even talk about hair.

None of those things is even close to correct. Wherefore the obsession with this one other thing?

"But why should I care whether the colour is processed correctly?

If it appears correct, what has its actual correctness got to do with anything?"

So, when you take your camera outside and take a picture on a bright day with indoor flash settings, I guess that doesn't matter either?

No, you're right. It doesn't matter.

Quote - "But why should I care whether the colour is processed correctly?

If it appears correct, what has its actual correctness got to do with anything?"

So, when you take your camera outside and take a picture on a bright day with indoor flash settings, I guess that doesn't matter either?

No, you're right. It doesn't matter.

Not if you get the effect you want, no. It does not matter.

And if you screw up and forget to adjust your white balance, (and I bet every digital photographer has at some point) and do not get the effect you want, it's trivial, trivial to fix after the fact.

Digital photographs are GC'd and almost all of them are trash. None of them is a perfectly accurate reflection of reality.

I shoot multiple exposures to merge into HDRI's. When I process them into PNG's, who knows what combination of gamma, luminance, saturation, light/dark point settings I'm going to use for any given image. Which of the many possibilities is correct?

And should I be hanged for shooting in monotone?

It's pretty clear to me you don't wish to use gamma-correction, Inklaire, or have Poser process colours correctly. And white balance settings on your digital camera are a means to an artistic end to you. Anything else is meaningless to you.

That's fine. For you.

You asked a question, and I answered it. What was your objective in asking the question in the first place? to discredit gamma-correction as a science? Or to justify your choice not to use the information given to you?  If you don't wish to use information found on these forums, it doesn't make that information of any less value to those that do use it.

hawarren: "Let me know if the GC image still looks washed out on your monitor. " 

Yes, that's better - to MY eyes and on MY ancient Viewsonic CRT which may have the gamma of an IBM 3270 terminal for all I know :-)

"Pardon the stupid question, but is it a hard and fast rule that GC has to be set at 2.2"

Well apparently so, if you want it to be correct.  To me, it's a control like any other. If backing it off make the image look better to me then that's what I do. I think that I understand the physically correct philosophy. I've been fascinated with science and technology my whole life, but art and science, like religion and science address different questions or the same question from entirely different points of view. Each is valid in their own realm but when they overlap it can get messy. 

Let us agree that it [GC] is correct* .* Let us also agree that what is correct* *is not going to be universally perceived as the best - because of variations in monitors, eyesight and Lord knows what other physical and psychological factors any more than N mg/kg of a drug is going to work for everyone, or everyone is going to agree on which one of the Bush twins is hotter - it's Laura - don't argue with me.

So the GC proponents say 'well maybe', while channeling Galileo and muttering 'and yet it is correct.'  Fine, message received and noted for reference. The skeptics will look and say 'you're selling snake oil.' Fine, do what pleases you. We might aw well be arguing art vs porn at this point, though the examples would be a lot more entertaining.

Someone correct my aging memory. Was there this much kvetching over GI/IDL? If there was, I don't remember it. That was a new feature to many people and it way promoted by some of the same folks evangelizing GC, but it seemed to go down a lot smoother. If so, why? Discuss among yourselves.

Bagginsbill is going to have a cow when he get's back and reads all this. :-)

Well, I did a lot of renders last night and today with all kind of settings: GC, exponential tonemapping, HSV exponential tonemapping, GC in the shaders and so on and I read the whole wikipage about Gamma correction, both the english and the dutch (which have some contradiction BTW), and there are some pros and cons for using gamma correction:
Gamma correction makes better shadows and highlights and if you want realism in your render that's a good thing. Poserpro GC makes it very easy to use it.
But, I use a lot of dynamic hair and I have to change all the shaders because they are much too red and too bright for using GC. Because they use procedural shading,and GC only works on texturemaps you get very different results than without GC.
All the textures of clothes and props I bought are optimised for non-GC renders so I have change all the shaders before I get the same result with GC.
I have to change all the lightsets I made because they were not intended for using GC.
That's probably the reason why I preferred tonemapping over Gamma correction.
So yes, gamma correction is an improvement, but you'll  have a lot of work to do before your renders look the way you like it.
We have a VSS-prop for skins and there's also one for transmapped hair, it would be nice if I could have one for dynamic hair and clothing

best regards,

Bopper.

Quote - It's pretty clear to me you don't wish to use gamma-correction, Inklaire, or have Poser process colours correctly. And white balance settings on your digital camera are a means to an artistic end to you. Anything else is meaningless to you.

That's fine. For you.

You asked a question, and I answered it. What was your objective in asking the question in the first place? to discredit gamma-correction as a science? Or to justify your choice not to use the information given to you?  If you don't wish to use information found on these forums, it doesn't make that information of any less value to those that do use it.

I wanted the point of GC to be explained to me so that I would feel justified in spending the time it takes to use it.

I'm disappointed that that hasn't happened, and that instead I've been persuaded that, not only is it not worth the time, but that I should probably be asking SM for a refund. So, yes, I'm a bit frustrated.

Well, I did keep the faith that in time someone would say something that would help me see the light, as it were, for a little too long.

Poser is clearly not the right software for me. Not a real loss, thankfully. Content works in other apps.

Quote - Bagginsbill is going to have a cow when he get's back and reads all this. :-)

No, I think he will shake his head sadly, and write another valuable Tutorial.

Quote - But why should I care whether the colour is processed correctly?

first of all, most of us can tell.  it's, imho, glaringly obvious in most works, including my own older heavily processed, filtered and even painted works.  we begin with the question to verify. 

second of all, it's like any trouble-shooting. you begin with checking if people have the right settings.  answers change based on how they respond.

Quote - If it appears correct, what has its actual correctness got to do with anything?

this question makes no sense.  if it appeared correct, even just to them, they wouldn't ask for help improving it.

Quote - We have people using lights without shadows. How does that fit into correctness? It doesn't.It's an attempt to give the appearance of correctness.

which is why most of the time, even before "did you use GC," we ask whether they have shadows turned on.  even if it looks like they're using lights with no shadows, people ask and check. 

and since lots of people use lights with no shadows to try to accomplish the same thing GC does (that's not a guess, i've literally been told that), that's yet another example of how you need to change your lighting to stop compensating.

Quote - We have figures with gross anatomical flaws and faulty joints. We have skins and flesh that doesn't react to surface collision with other objects. We have muscles that don't flex when we change figure poses. Spines with 2 joints. And let's not even talk about hair.

None of those things is even close to correct. Wherefore the obsession with this one other thing?

it's not an obsession.  it's simply addressing one of the many problems we can.  just like phantom3d and odf are addressing the problems they can with their figures.  just like most of us using linear workflow use bagginsbill's fresnel equations.  i use Matmatic now (for lots of reasons), and i can generate lots of different materials quickly and easily.  i incorporate features like conservation of energy, accurate fresnel equations, and linear workflow automatically for all of my materials.  i rarely think about them at all.

light is the common denominator in visual art.  no matter what genre, people expect some connection to how light works in real life.   not using linear workflow is like applying a random, extreme curve filter to all of your work.
at the end of the day, the proof is in the pudding.  not just according to anyone in this thread, but people in general.  bagginsbill is a "guru" for the very simple reason that when he posts his results, people like them.  they want to do the same thing.  they pay attention to what he says only based on his results and of those of us that use his advice, tools, materials, etc. 

some people want to get as far as they can with realism in Poser, and i think most are less satisfied with lighting and materials than figures, clothes and props. 

there are no nodes that can work correctly with sRGB input.  there's no way to tell someone the correct (or as correct as possible) way to make anything without linear workflow.  what bagginsbill knows is physical accuracy, and that's the basis for advice he gives.  it's fine to ignore his advice, but those that follow it make their choice based on renders, not hype. 

those of us that use linear workflow do so because it solves a problem for us, and solves it efficiently.  many of us can see a clear difference.  if you personally can't see the difference, or don't want to learn to work with it, don't.  everyone posting to this thread  who uses linear workflow is saying not to use it if you don't want to.  what response are you looking for?  that we shouldn't use it?  that we have no reason to do so? we do.  we found that it improved our work.  as someone who heavily postworks, i found it worlds better to have a more realistic base than one where all of the shading is just plain wrong. 

please stop making strawman arguments like  "you can have realistic results without GC," which we acknowledged from the start, "if you like how uncorrected workflow  looks, why change it?" which we never suggested, and "this is against artistic license, stylistic extremes and postwork," which none of us has said and many of us use.

instead of just saying there's no clear explanation, could you say what's wrong with any of the explanations so far?  just to reiterate.

• all digital images that don't explicitly use another color space and all monitors, digital cameras, cell phones, etc. (which means the colors displayed in your color picker) work in sRGB space. 
• all renderers work linearly.
• if you don't translate input to linear form, the calculations renders make are incorrect.
• if you don't  translate the rendered result to sRGB, the monitor can't display those calculations correctly.

this is not a simple case of lighter/darker or more/less saturated.  all of the shading is off, and both highlights, shadows and everything in between are incorrect in different ways.  highlights are too bright, shadows are too dark, and the shading between them doesn't progress properly.

GC equations are simplified approximations that will give you visibly lightened shadows compared to using sRGB equations.  they are themselves not quite correct.  i actually saved bagginsbill's tests, and he once gave me permission to repost them at another forum, so i think i can repost them without totally stepping on his toes if people are interested.  i can't find them to link to.

GC in Poser Pro affects all color input. that includes colors for procedural textures.   bagginsbill rarely uses textures, and pretty much only does so on human figures.  if you notice, his most recent material posts don't include GC because he's using PP 2010. i'm pretty sure that you actually have to be careful about GC and intensity maps that you want to leave as is.

Quote - > Quote - > Quote - Pardon the stupid question, but is it a hard and fast rule that GC has to be set at 2.2 if you're using a PC?

Couldn't it be set at 1.2 or 1.3 if less of the effect were desired?

Good question actually.  There's no hard and fast rule that GC has to be set at 2.2 if you're using Windows.  We use the gamma values of 2.2 for Windows and 1.8 for MacIntosh because that's what most monitors have.  I don't see why you can't experiment with other gamma values.
 

Here's why.

Thanks for the valuable wiki page on gamma correction.  After reading this page and a few more on the web, I've come up with the following simplistic understanding of gamma correction.  Please don't hesitate to correct me if I'm wrong.

Computer monitors do not display materials linearly. If the input luminance is 0.5 and a monitor's gamma is 2.2, then the output luminance is not 0.5 but 0.5 to the power of 2.2, which is 0.2176. Therefore, for an image whose luminance is 0.5 to appear with correct brightness on a monitor that has a gamma of 2.2, the brightness of this image must be raised to the power of 1/2.2 so that the output brightness produced by the monitor is correctly set at 0.5. When a JPEG is saved on a monitor that has a gamma of 2.2, the JPEG algorithm encodes the file with the appropriate gamma correction by raising the image's brightness to the power of 1/2.2 (most Windows monitors).  On a MacIntosh, however, the file will be encoded with a gamma of ~1/1.8.

A JPEG saved on a MacIntosh looks darker on Windows because it is decoded with a gamma of 2.2 instead of 1.8.  The inverse is true when a JPEG saved on Windows is dipslayed on a MacIntosh.  The image will end up looking brighter than it should.

If we do not know exactly where a JPEG comes from, we can only guess that the gamma value applied to the image must have been 2.2.  It could have been anywhere between 1.8 and 2.3.

In such cases we need to experiment with different gamma values.  Am I somewhat correct?  Please do not hesitate to correct me if I'm wrong.

Grimmley, The second image looks better on my monitor.

So I've been back for two days and haven't commented. I actually lay in bed till 3 AM this morning, disturbed by what I'd read here. Yes, I've had a cow.

What really troubles me, more than the refusals to simply read what has been presented in the past to the tune of THOUSANDS of posts about GC, is the mis-representations of things I've said. I never said GC is some sort of cure all nor that you can only produce crap without it.

I have said there is a lot of art that shows the symptoms of not having GC or any other attempt to compensate for the sRGB color space we all see with, because we all deal with digital images and we all use digital devices that EXPECT sRGB images, regardless of whether they are photos or renders.

But more than all that, what really upsets me is the mischaractarization of postings in other threads, arguments about communication style, and the total bonehead arguments about t-poses and other dumb stuff. Seriously? You want me to spend 100 hours making "art" to demonstrate a simple skin lighting concept, comparing the difference between a couple settings? Pay me.

And that time I said "try VSS, then come back" was not the way it was represented here. It was not at all a case of me saying "use GC first or I won't talk to you". The poster needed help to make skin more realistic. I have written thousands of hours on that subject and posted over 1000 images about it and provided free software and shaders to make it a 5 second operation to fix skin. I asked the poster in that case to give VSS a try, and then if that didn't fix all his problems and completely blow him away, then he should come back and I'd give more specific help around the specific lighting and textures he was using. No way was that rude. And he was blown away and did not need more help, as far as I recall.

You who like to mispresent how I talk and then complain about it really irk me. The mods here have repeatedly stated that it is inappropriate to demand a specific communication style from others, particularly when you're complaining about how somebody is helping someone.

Bah.

People - do searches. Search for the word "crap", posts by me. Yes I use the word. No, I was not rude.

I also really am pissed about claims that I promote GC because I'm affiliated in some way with SM and this helps them.

That is the stupidest insulting part of this discussion.

Go back and read my posts for 5 years, trying to figure out why skin doesn't look right in Poser. Go read what I learned when GC came out. At that time, I was a user, nothing more. I did not work for SM.

Go read my astonishment at the difference it made when Poser Pro came out.

Then go read how I developed hundreds of ways to do it WITHOUT BUYING ANY NEW VERSIONS OF POSER.

Are you people so stupid? Did you think that SM was happy that I posted how to get GC done WITHOUT buying Poser Pro over and over? Do understand the ramifications of that? How could I be accused of some sort of nefarious "evangelism" when what I was teaching actually hurt SM's sales?!?

Perhaps it isn't clear, so I'll spell it out for you insulting bastards.

I published how to avoid giving SM more money for Pro features by using Poser 5, 6, and 7 materials to do the same thing.

I'm not asking you to buy anything or use anything. I'm simply sharing what I know. Yes there is always more than one way to get something done. And some of those ways are my favorites, and I understand them really well, and I talk about them, because they are the fastest easiest ways to get lights to behave as you'd expect, instead of getting stuff you don't want.

Double bah!

I'm going to a party now.

Go read this. I thought I already explained everything.

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2757170

Note in the opening statement I said:

"You need to use gamma correction. I don't care if it's in your postwork, or you use Poser Pro, or you use gamma correcting shaders, or you use a GC lens. Take your pick."

Yes, it's my opinion you need to deal with it, but if Photoshop levels is your choice, that's fine. I never said you had to use Poser Pro or GC shaders. However, there are reasons to do it in-render, although such reasons do not apply to every situation. To use an analogy, if I suggest you should try limes in your cocktails, doesn't mean I reject lemons, nor does it mean I demand limes in everything you eat or drink. You guys need to stop putting words in my mouth.

Go look at the images in the linked thread. If you say you can't tell the difference, you're a liar.

GC does not apply only to texture-based shaders. It applies to all colors except black and white, whether they are procedural or image based.

In particular any shader involving incomplete (Fresnel) reflections will look very wrong without GC in shader or renderer.

applauds BB

Quote - > Quote - Thanks for the feedback Zaycrow.  I will further reduce the intensity of the IBL light and crank up the spotlight just a bit to see if we can get the GC'd image to look more 3D.  What kind of monitor is your old monitor?  And your new one? (if you wouldn't mind)

 

Well, that's the problem -  if you crank up the CG my new monitor will show it as too much gamma control. My old monitor see it ok, but that's the problem with LCD's. At work we still use CRT screens and those old things still show the CG images here as too much gamma corrections.
My old monitor is a LG 19". My new monitors are Phillips Brilliance 20" 200W and Samsung 30" 305T plus.

Ah, the good old CRTs.  I remember having clung to my Sony CRT for as long as I could when everyone else began to have LCDs because the Sony CRT monitors displayed colors much more accurately than the early LCDs.
 

This is the other thread you should read.

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2762503

Read the opening post for WHY - It's quite clear. Copied below with emphasis.

=====

I know, I'm becoming an ass about this. But I'm really tired of seeing linear-encoded renders.

None of us has a display device encoded in linear color space. We all have monitors and printers that show images correctly if they are in sRGB color space.

Linear color space is similar to sRGB color space. It is not the same.

Inches are similar to centimeters, too, but you can't just replace one with another.

In sRGB color space, the value .5 is not 50% as bright as 1. It is only 21.7 % as bright. Please stop posting renders for devices nobody owns. Or, **when you post such images, apologize to the viewer for making them look at something you could easily correct, but you refuse to.
**
Thank you.

When you refer to MAC's, keep in mind that the standard is just now changing to accommendate a Gc=2.2.  Earlier MAC OS's still do exhibit a Gc=1.8.  Brighter screens, better sales.  Good marketing strategy. 

Also keep in mind, digital cameras, scanners, printers and the internet have a Gc=2.2 standard globally.  But it is not an ironclad rule that your renders must rigidly adhere to that standard.  As long as you have a measure of control over your midtone range, you can tweak the settings to suite your needs within your working environment.  If the image is going to be displayed globally, then you may want to reconsider how it is rendered to conform to standards.

Welcome back, BB.  Hope you had a nice vacation.

Quote - hawarren: "Let me know if the GC image still looks washed out on your monitor. " 

Yes, that's better - to MY eyes and on MY ancient Viewsonic CRT which may have the gamma of an IBM 3270 terminal for all I know :-)

Thanks for the feedback lmckenzie.  A Viewsonic CRT???  COOL !!!  I too used to have a Viewsonic CRT in my youth, although my favorite was still my dear old Sony CRT. 

Quote - > Quote - It's pretty clear to me you don't wish to use gamma-correction, Inklaire, or have Poser process colours correctly. And white balance settings on your digital camera are a means to an artistic end to you. Anything else is meaningless to you.

That's fine. For you.

You asked a question, and I answered it. What was your objective in asking the question in the first place? to discredit gamma-correction as a science? Or to justify your choice not to use the information given to you?  If you don't wish to use information found on these forums, it doesn't make that information of any less value to those that do use it.

I wanted the point of GC to be explained to me so that I would feel justified in spending the time it takes to use it.

I'm disappointed that that hasn't happened, and that instead I've been persuaded that, not only is it not worth the time, but that I should probably be asking SM for a refund. So, yes, I'm a bit frustrated.

Well, I did keep the faith that in time someone would say something that would help me see the light, as it were, for a little too long.

Poser is clearly not the right software for me. Not a real loss, thankfully. Content works in other apps.

Huh?

I'm not sure what you are looking for. If you need more justification for doing things correctly than what's been presented on this thread, I don't believe there IS help for you. The arguments against linearising your colours (including shades of grey) before processing have not even addressed the question, and I really think you are reading those statements and find them more compelling. What about colour accuracy do you find trivial? I just don't get it.

Quote - hawarren: ty for the link - exceptional quality work- yes I like

Apple_UK.  Above are before and after images of Basile.  Left image is non-GC, right image is GC.  Bagginsbill's VSS skin shader was not used.  I simply turned on the GC option in the render settings.

I hope you can see on your monitor that the GC image has more clarity and the yellow bloom is gone.  Let me know if the GC image looks washed out on your monitor.  I will adjust the lights for you.

Please note that above images are simply test renders at very low resolution.  They certainly do not represent the true beauty of Basile's textures when rendered in high res by a talented artist such as Atlantistyle (my apologies to AtlantiStyle for posting these crude images of his masterpiece). 
 

hawarren - strong case for GC - it has managed to turn a plastic person into something very usable,

Can you tell me where  do I get the shaders for GC and VSS  fom please?

If you are using PoserPro (any version), Apple_UK, then GC is inbuilt in the programme - it's a tickbox and a number setting.
If not, it's a bit more complex. And I really think this is where people are having issues: GC is NOT a simple solution, despite Bantha's wacro.
I'd be happy to hand hold you to as far as I've been able to go with this... it's a bit time-consuming, but well worth it in the end, from a colour-accuracy standpoint, that is.

VSS is a shader-distribution tool developed by BagginsBill for complex figures. He has included skin shaders in the tool to illustrate its use. A link to the most recent one (along with the tool) can be found in BB's signature tag.

RobynsVeil - One nurse to another - Your offer is kind. I have just DL the two and will play with them but I think I shall be forced to seek your hand  out later :)

I'm happy to help you, Apple_UK - as much as I can. There are still a few grey areas in my mind about getting things like Reflection and Refraction to play nicely with GC (and conservation of energy, another cool light concept to get the head around), but the basic stuff I feel confident I'm pretty clear on.

Quote - When a JPEG is saved on a monitor that has a gamma of 2.2, the JPEG algorithm encodes the file with the appropriate gamma correction by raising the image's brightness to the power of 1/2.2 (most Windows monitors).  On a MacIntosh, however, the file will be encoded with a gamma of ~1/1.8.

A JPEG saved on a MacIntosh looks darker on Windows because it is decoded with a gamma of 2.2 instead of 1.8.  The inverse is true when a JPEG saved on Windows is dipslayed on a MacIntosh.  The image will end up looking brighter than it should.

If we do not know exactly where a JPEG comes from, we can only guess that the gamma value applied to the image must have been 2.2.  It could have been anywhere between 1.8 and 2.3.

In such cases we need to experiment with different gamma values.  Am I somewhat correct?  Please do not hesitate to correct me if I'm wrong.

not hesitating to correct you ;D.

Wikipedia

Quote - Many JPEG files embed an ICC color profile (color space). Commonly used color profiles include sRGB and Adobe RGB. Because these color spaces use a non-linear transformation, the dynamic range of an 8-bit JPEG file is about 11 stops. However, many applications are not able to deal with JPEG color profiles and simply ignore them.

afaik, Poser does not support reading color profiles.  that's not what makes you need to linearize your texture.  if the images are  created by a digital camera or scanner, those devices use sRGB space.  if you paint a texture, you see it through an sRGB device, so in that sense, the monitor will affect your image.  but not in the sense you seem to mean. 

it will just mean that when  you choose a color that looks right to you, it looks right to you on your monitor.  you could create linear versions of your images without Poser  (though i don't know how one would do it mathematically in Photoshop, and i'd hate doing it by eyeballing it myself).  conversely, if you use the right color space within Photoshop, you could probably set it up so that you create linear works that look like they're sRGB when you're editing them in Photoshop.  you could also work in other color spaces, like CMYK or Pantone colors.  it makes no difference to the JPEG itself. 

the issue is more that if it looks right on your screen, the renderer can't work with it.

in my experience, the difference between Mac and PC was easier to handle in post than the difference between GC equations and sRGB equations.  or actually, pretty much ignore and just use the same principles of making images that work in general on the web.  just like the sRGB printers and other digital devices do, in my expeience it's best to work to the specification.  at least for the raw render.

Quote - So I've been back for two days and haven't commented...

This immediately came to mind... :lol:

www.youtube.com/watch

Good to see you back, BB!

Jump in anytime, BB... I'm sort-of over this, now.

@Apple_UK:  Are you using PoserPro or PoserPro 2010 (forgive me if you indeed mentioned it elsewhere and I have forgotten)?  The VSS skin shader template has builtin Gc nodes and will need to be adjusted accordingly if using Poser Pro series.  You would like no Gc in your shaders, so the value must be reset to 1 in 5 separate zones.  I am detecting overbrightness in the eye whites in the Gc renders, indicating to me that there is too much correction being applied.

hborre: P8 and you're right about the eyes, in all the pics I think. I have rather neglected understanding eye shading I'm afraid. I must do something about that. I shall also do something about that right nostril.

Okay, P8 will require that material Gc be active and set to 2.2 (if using PC).  Another user did notice a slight brightness in the eye whites and made an adjustment to a node value there.  I need to revisit that shader group to determine which node needs to be changed.

Just throwing an idea in here - that looks like the Pr2 eye shader of BB's? - but I wonder if doing a bit of conservation of energy might help, maybe? Just a thought.

It's actually the PR3, Robyn.  Very little was changed for that particular zone in the VSS.  The gamma misbehaves because it is dealing with white texture, over-saturating it.  Reducing the gamma value brings it back to normalcy.  Perhaps applying some change to Gc (1.5 - 1.8) and adjusting the Diffuse may bring better, pleasing results.

Thanks for that, HBorre. Just running some GC and lights tests for JoePublic... might try to do a bit of CoE on that afterwards to see if it makes a difference, unless BB comes in with a better idea. :biggrin:

It will be interesting if you come up with something a little bit more intuitive.  I don't recall seeing this effect in PoserPro or PP 2010, so I will pay closer attention next time I render. 

Quote - > Quote - Interesting. Are we trying to emulate the camera lens, or human vision? Would they be the same?

You cant Emulate human vision... its impossible.

Actually so called
photorealistic 3Drenderers  are just Emulation what the scene would look like if a professional photographer took a picture and handed it  to you
if you  use a  truly "highend"
render engine that used a "physicaly correct" workflow you can recognize this right away in your settings ( see pic)
but these of course are way more $$Expensive$$$ than poser

I think that is an interesting question that deserves a more accurate answer. Much of The Renaissance was about artists recreating what they actually saw on paper and canvas rather than caricatured and stereotypical shapes previous generations used.

Take a look a Durer's perspective device, the second image down. You can see how artists in the days of the old masters were taught perspective and foreshortening. This method is still used to teach art students today, though using clear plexiglass plates rather than a bulky table.

Actually, take a look at some old master paintings and how good they were at capturing realistic behaving light and shadow. They had many of the techniques of photorealism down centuries before photography was invented! In fact, to this day, photography owes more to painting (which is also the style of much 3D art) than vice versa.

If you are interested, take a look at this fascinating -certainly in the context of this discussion- article from a few years ago, the "White's Illusion" that plagues the human brain can also occur in "any system that tries to emulate human vision." (quote from the article, emphasis mine)

In fact the camera is a machine that emulates human vision.

But for the original question, no a camera and human vision are not the same. 3D software imitates a real world lens with many of the same controls, but not the human eye. Generally speaking artists try to capture a mix of what they see and imagine on their medium, and of course there are extremes in either direction.

Quote -
If you are interested, take a look at this fascinating -certainly in the context of this discussion- article from a few years ago, the "White's Illusion" that plagues the human brain can also occur in "any system that tries to emulate human vision." (quote from the article, emphasis mine)

So what does it say about me that "White's Illusion" looks like two equally grey boxes to me. I have to really do some concentrating to get the one on the left to look darker.

Quote -  

Quote - hawarren: ty for the link - exceptional quality work- yes I like

Apple_UK.  Above are before and after images of Basile.  Left image is non-GC, right image is GC.  Bagginsbill's VSS skin shader was not used.  I simply turned on the GC option in the render settings.

I hope you can see on your monitor that the GC image has more clarity and the yellow bloom is gone.  Let me know if the GC image looks washed out on your monitor.  I will adjust the lights for you.

Please note that above images are simply test renders at very low resolution.  They certainly do not represent the true beauty of Basile's textures when rendered in high res by a talented artist such as Atlantistyle (my apologies to AtlantiStyle for posting these crude images of his masterpiece). 
 

I agree that the yellow bloom is gone, but so it the contrast and the detail, all gone because of the use of CG. The yellow bloom is annoying..... but so is the lack of contrast and detail.

I really don't care if BB or anyone else is getting a fit or not, I simply don't use CG on each image anymore. I'm sick of looking at images that lack any detail and contrast. If I've got problems with too dark areas or blooms, I'll adjust light settings and use Tone Mapping in P8, instead of using CG and settling for images that may be brighter but lack all the rest.

I'm not a pro...... since CG is a pro features I don't seem to be needing it, according to SM.

As for the threads with images BB has pointed out, of course the images show benefit from CG. Imo, most of them are lighted so badly, that any postwork done on them will make tons of difference. Those images do not support the case at all, the only thing they may show is that badly done images may benefit from CG. If you use Cg on a well done image, you will get very different results, which will show that using CG on every image may not be such an idea. I use CG, but not just bluntly on everything.