Talk:Middle gray

message: The table says absolute whiteness. Shouldn’t that be, as seems to be the case elsewhwre on the page, absolute neutral gray?
174.89.73.243 (talk) 12:44, 10 February 2016 (UTC)
replies: text: It should probably say Linear Arithmetic, as there the article appears to be attempting to explain that  50% is the reflectance value one obtains if one naively divides 100% (that "absolute whiteness" : perfect reflectance value) by two. i.e. If one derives a logical, although not very useful or perceptually relevant, reflectance value for "mid grey" by calculating the linear (arithmetical) mean of 0 and 100. A rather minor concern however, as the "article" is a disgrace in its entirety: A mess of mostly unreferenced misconceptions, mistakes and gibberish. Someone with some knowledge of the subject and nothing better to do needs to re-write it.  — Preceding unsigned comment added by 47.232.225.116 (talk) 12:33, 4 July 2020 (UTC)
thread_title:  Absolute *whiteness*? 

message: Because the article itself uses white as a background colour, the box allows us to compare the tone only against white, but not against black. But the point of being a middle grey is to be in between black and white, and the demonstration should allow us to compare the tone against both.  — Preceding unsigned comment added by 80.114.146.117 (talk) 18:19, 19 January 2017 (UTC)
replies: text: Makes sense.  — Preceding unsigned comment added by 77.61.180.106 (talk) 15:47, 24 March 2021 (UTC)
thread_title:  About the tone demonstration box on the top-right 

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thread_title:  External links modified (January 2018) 

message: What is your source for the 18% gray card information? Did you arrive at the values empirically? By definition the 18% gray card should have a reflectance of 18%, whiteness = 0.18 and srgb = 0.4614, similar to the row labeled L*a*b, for an L* = 0.50 (D65, 10-deg). Is your 20% value based on a white point of 90% (0.18/0.90 = 0.20)? If so, it might be nice to foot note your calculation.
Bz60zd (talk) 22:50, 2 July 2018 (UTC)
replies: text: One might well presume so. Unfortunately no reference or explanation is offered for why 18% is misrepresented as 20%. I think, from vague memory, the conversion of 18 to the less accurate but more precise 20 originated with either Ansel Adams or the Kodak company?  — Preceding unsigned comment added by 47.232.225.116 (talk) 12:44, 4 July 2020 (UTC)
replies: text: I think the 20% figure is just wrong. At least Kodak claims their grey cards have 18% reflectivity. I think the source of the confusion is that 18% is a fifth of the 90% reference white that's often found on the reverse of the grey card.  — Preceding unsigned comment added by 77.61.180.106 (talk) 17:27, 26 March 2021 (UTC)
thread_title:  About the "Table of middle grays" 

message: According to some statistics I found online, the following ratios are currently common:
1    	 76,54%
2    	 13,13%
1¼   	  3,88%
3    	  1,92%
1½   	  1,85%
Other	  2,69%
Total	100,00%
Considering how common faulty image interpolation is, that means the test pattern image may appear too dark for 23% of our readers. Is there anything we can do? Can we possibly create a CSS test pattern for example? Because as it stands I'm wondering if it's wise to show the test pattern at all...  — Preceding unsigned comment added by 77.61.180.106 (talk) 10:29, 24 March 2021 (UTC)
thread_title:  About CSS px and device pixel mismatch and the resulting problems 

message: Missing: 50% grey levels in newer colour appearance models such as CIECAM02.  — Preceding unsigned comment added by 77.61.180.106 (talk) 18:28, 24 March 2021 (UTC)
replies: text: Hmm, 77.61.180.106 added two patches for the CAMs. The issue though is that these colors are specified with TRANSPARENCY -- what is going on here? And we do have standard viewing conditions in CAM02-UCS. Artoria2e5 🌉 11:00, 29 March 2023 (UTC)
thread_title:  CIECAM02 

message: Do we really need so many sRGB columns in the table? In the end, sRGB is just a colour encoding scheme, it has little physical or perceptual significance. The last column is useful to actually show the greys, but I don't see the use of the others. And if you did somehow need those values, you're enough of a specialist to do the conversion yourself.  — Preceding unsigned comment added by 77.61.180.106 (talk) 18:37, 25 March 2021 (UTC)
replies: text: Arguably, it has a rather large cultural significance, being the default colorspace in a vast array of applications including HTML/CSS colors. Spidermario (talk) 21:00, 25 January 2023 (UTC)

text: No reaction for over a year, so I take it there are no complaints. I will take those columns out and perhaps see if I can think of something useful to replace them with.  — Preceding unsigned comment added by 92.67.227.181 (talk) 14:22, 28 May 2022 (UTC)
thread_title:  sRGB columns 

message: After removing all the invalid gammas only the old Mac gamma and the trivial case were left, so there was no longer any point in keeping it.
But taking a step back, what use could this column have been anyway, even in an ideal world where simple gammas described all transfer functions? What are gamma values used for? To convert between simple gamma compressed colour spaces. So if your colours were in colour space A and you wanted them to be in colour space B, you'd combine the gammas. But if you're in that scenario would you type ‘Middle gray’ in the search box? No. You'd open your graphics application and change the colour space. Or if you're a programmer writing a graphics application, you'd look up the articles for the colour spaces you want to support and code the transfer functions.
In what scenario would you look up ‘Middle grey’ with the intention of performing a calculated brightness change? Not if you just think your picture isn't pretty enough, you'd just tweak the curves manually or fire up your HDR tool. You'd do it only if there's an area in the picture that you definitively know should be middle grey. Maybe there's a test card in the picture. And you absolutely require it to be correct, regardless of how pretty or ugly the resulting image will be. Maybe it's a scientific image. Well, I feel scientists can take care of themselves. But in that case, you'd first check to see if whatever caused the problem didn't cause other problems that require a reshoot. Was the reference light okay? Were no unexpected non-linearities introduced? Then you'd use a graphics application to convert to linear light, scale and convert back. You wouldn't bother with gammas yourself and you'd only consult this article if you'd forgotten the exact figure for the brightness of middle grey.  — Preceding unsigned comment added by 77.61.180.106 (talk) 01:44, 26 March 2021 (UTC)
thread_title:  Gamma column 

message: Quoth the article: As early as 1903, middle gray was defined
However, through a careful reading of the cited source a different picture emerges. The authors drew for their understanding of the topic substantially on Grundzüge der physiologischen Psychologie by Wundt, which I have also consulted. The figures they give are part of a calculation example, probably inspired by an experiment described on page 374 to determine the relative brightness of black pigments compared to white cardboard, to illustrate the then common understanding under scientists, though not, presumably, among their audience, that our experience of lightness falls on a logarithmic scale. This is also the underlying principle of the Zone System by Ansel Adams. On a logarithmic scale, there can be no absolute middle grey, but you can determine a middle grey between two arbitrary tones in the way described. It's important to stress however that it's clear from the exactness of the figures that it's just a calculation example, the authors were encyclopaedists and didn't do any experiments themselves. Had they done so, they would have made a surprising discovery!  — Preceding unsigned comment added by 77.61.180.106 (talk) 15:10, 30 March 2021 (UTC)
thread_title:  1903 

message: The image included by the following syntax:

Will actually be formatted by the wiki syntax renderer using a src and srcset like this:
 //upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Black-white-1px-checkers.svg/50px-Black-white-1px-checkers.svg.png
 //upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Black-white-1px-checkers.svg/75px-Black-white-1px-checkers.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Black-white-1px-checkers.svg/100px-Black-white-1px-checkers.svg.png 2x
This means that on a 144 pixels per inch device, the image 75px-Black-white-1px-checkers.svg.png will be shown. (And that in this case ‘image-rendering: pixelated’ won't do anything.) You can look at that image and easily convince yourself that it can't have the right average brightness: in the centre, about half of the pixels is black, a third grey and a sixth white, and near the top and bottom edges about a third is black, a third dark grey and a third white, giving an appearance that is far too dark overall.
I've hacked the srcset away to see what would happen, and the result is alternating vertical bands that are far too bright and far too dark, making it hard to judge the proper grey level. The reason for this is that within such a vertical band, the ‘image-rendering: pixelated’ consistently duplicates the white or black pixels while picking the other only once.
But even on a 96 pixels per inch device it may not show up correctly, because displays often don't like such sudden black / white transitions. This is why gamma correction utilities tend to use horizontal lines only. Near the transition the colour may be just a tad dark or light and when this happens it tends to be consistently skewed in the same direction.  — Preceding unsigned comment added by 77.61.180.106 (talk) 16:55, 20 May 2022 (UTC)
thread_title:  The checkered image doesn't render correctly. 

message: I've looked and looked and looked and I cannot find any reference to 18% grey cards before Munsell, Sloan & Godlove 1933 and the ones I can find are only a couple of years later. In this here article 18% is specified as the colour of a grey card but I don't think that's really what it is: it's the midway point found in the 1933 paper and grey cards tend to follow this. And Kodak at least claims the following: https://www.kodak.com/en/motion/page/gray-cards (Munsell Color is a division of X-Rite. Not surprisingly, it's the division behind the X-Rite ColorChecker: https://munsell.com/color-blog/color-reproduction-photography-printing-television-40-years-colorchecker X-Rite also owns Pantone.)
Now, to get back to the 1933 paper, four of the observers were the authors and an assistant. It would be very surprising if the rest weren't insiders as well, all people who knew what a N5 was supposed to look like (in its 1929 incarnation). So they were always going to get something near 18% back and the results of their experiments were largely baked into the starting conditions, if you get my drift.  — Preceding unsigned comment added by 92.67.227.181 (talk) 17:08, 8 June 2022 (UTC)
replies: text: @implications for commercialisation: A problem with that line of reasoning is that according to Priest, Gibson & McNicholas 1920 and Kelly, Gibson & Nickerson 1943 the values did in fact change. But then I look at Sloan's curve again and the rest of it and I just cannot shake the feeling that something is wrong.  — Preceding unsigned comment added by 92.67.227.181 (talk) 08:25, 13 June 2022 (UTC)
thread_title:  18%