Chroma Information (the Grid Illusion)

This is interesting—it's called the Grid illusion. A color grid is laid over a black-and-white image and, for most of us anyway, our minds fill in solid colors to an impressive degree. Here's the picture on the TYWKIWDBI blog. The red grid over the faces doesn't really work for me, but it's difficult to believe that the yellow, green and blue T-shirts only have color grids laid over them, and that our brains do the rest.

Here's the picture with the grid lines blocked out.

That's how hand-coloring works. A long-ago girlfriend who worked for The Washington Post and did graphics for local television stations was known for her hand-colored B&W photos, and I was always amazed how little detail or precision her colors could have and still work. (She sometimes used colored pencils on matte photo paper and sometimes Marshall's Oils, once a standard for that sort of work and still available from places like dickblick.com.) She was sanguine about colors bleeding over into the wrong areas (or not coloring all of an area), breezily saying things like "it'll look fine." And it did, she was right. I think she knew intuitively how little added color could suggest solid colors to viewers' eye/brains.

The look was that of old colorized postcards, which can have a sort of charm. Of course the colors didn't necessarily have to have much relation to the real colors of the scene, which also bothered me; you could photograph an orange sweater, print it as B&W, and hand-color it green with no one the wiser.

The legend on the grid illusion photo leads us back to some posts by Øyvind Kolås who calls it a "color assimilation grid." His comment: "luminance is a lot more important than the chroma for our visual perception." True, that.

I've guessed in the past that this might be one reason I like B&W more than color...because for some reason my brain is more sensitive to luminance and less to chroma than the way most people perceive things. I know that when I was very young I used to have an innate sense that colors "got in the way" of seeing...no idea how much that might have been due to suggestion or conditioning, but I recall the feeling. When we first got a color TV I was uncomfortable looking at it, and much later I bought one of the last B&W TVs you could buy. In art class and with coloring books I would complain that I never knew what colors to make things (I remember saying to my first grade teacher, when faced with a blank coloring-book page, "but what color is that?"), and I would sometimes complain that there were "only a few" colors...as if all oranges were the same and all blues the same, etc.

And on the other hand I've learned that some other people have a much more visceral, immediate, or emotional connection and response to colors than I do. A clue for me was that Szarkowski disliked Outerbridge because he couldn't stand his colors. In high school art class my bête noire (although we were friendly) was a girl who would churn out paintings at high speed, foregoing detail and edges. Very broad-brush—literally. Her work disturbed me. In retrospect I think she was very sensitive to chroma and what she was doing was putting colors together, because that's what was important to her and it was how her brain saw. And I just didn't get it at the time. It's what Rothko does, only he foregoes all figuration and she hadn't gotten that far. My pencil and pen-and-ink drawings were the opposite: detailed and precise, but monochrome. 

(I do have a strong sense of color harmony. I tend to prefer color photographers who actually actively use color as a primary creative element in their photographs, rather than those who simply photograph in color and don't seem to pay any attention to what the colors are. I should expand on that sometime...but some other time.)

I suspect we each have our individual relationships to color, perhaps even to chroma v. luminance. It's worth interrogating yourself about, anyway.

Mike
(Thanks to Stan B. for the first link, and it's not his blog.)

Book of Interest:

Photographs Not Taken: a collection of photographers' essays, edited by Will Steacy (Daylight Books; Second Revised ed. edition, 2012). Recommended by Mike Chisholm, who has good taste. This is a link to Amazon from TOP.

Original contents copyright 2020 by Michael C. Johnston and/or the bylined author. All Rights Reserved. Links in this post may be to our affiliates; sales through affiliate links may benefit this site. As an Amazon Associate I earn from qualifying purchases.

(To see all the comments, click on the "Comments" link below.)
Featured Comments from:

Albert Smith: "Many people are enthralled with the monochrome-only Leica cameras, and on various Fujifilm sites the wish for that brand to put out a similar B&W model usually comes in near the top when people discuss what Fujifilm should do next. I watch YouTube videos from street photographer Alan Schaller who is a master of black and white shooting. His advice video, '7 tips for black & white street photography with Alan Schaller,' says that you should go 100% mono, you can't get good switching to color at will. So this philosophy would add validity to the mono-only cameras. But try as I might, stalking the streets with my Fuji set to Acros, I'm always seeing color even when my EVF is showing black and white. A bright red car parked in front of a blue wall forces me to switch over to color, I can't just accept grey on another shade of grey. I don't think I'd be able to go out with a mono Fuji if they made one. And I was happy when I could afford my first color TV."

Mike replies: Ctein and I disagree about this, but I agree with you and Alan Schaller. I see how the camera sees. So if the camera sees color, pretending it doesn't doesn't work for me. But I had no problem at all shooting B&W exclusively for two decades. Ctein claims it doesn't matter to him, that he can shoot either one at will—at which point in such discussions, I usually remind him that he's not a B&W photographer.

Bob Keefer: "I've made hand-colored black and white photos for more than 20 years. In the beginning, I carefully colored within the lines, sweating every fluttering leaf in a landscape. But I soon realized those photos looked less compelling than the looser ones, usually on throw-away prints, that I did while experimenting with various color combinations. Soon my work became more painterly—and much more convincing. As the photo on the TYWKIWDBI site shows, our eyes do a great job of matching hues with natural boundaries."

Geoff Wittig: "There's a well-known saying in the world of representational painting: value does all the work, and color gets all the credit. Value is the light to dark scale, or black and white. Viewers (and buyers of paintings) often respond emotionally to a painter's color palette, but it's the light to dark value structure that determines how a painting 'reads' from a distance, and that draws a viewer in for a closer look. Emotional mood, sense of atmosphere, the illusion of distance and deep space in a painting? All are largely determined by value, not color. In fact, within surprisingly broad limits, a wide range of color choices will work just fine to create a realistic-looking painting, if the value structure is correct. The one property of color that is important for paintings to read as authentic is color temperature, meaning warm to cool, roughly from the red/orange warm end to the icy cold cobalt blue end of the visual spectrum. This will be immediately familiar to photographers used to employing warming filters for pleasing portraits, or photographing a landscape in the warm light of a setting sun."

Not THAT Ross Cameron: "The way the human brain works in fascinating. Just look up the homunculus fallacy.

"I can recommend Vision and Art: The Biology of Seeing by Margaret Livingstone. B&W and Chroma vision are processed through different parts of the brain. B&W vision / outlines / edges etc. came first, and chroma is a later evolutionary adaption for animals that are active during the day—I think for identifying plants etc to eat or avoid. Night vision has little to no need for colour.

"She outlines many visual effects that trip the differences in processing—including that colour does not need to fill the boundaries. She explains the science known at time of publishing, and notes her speculations as such too. Thanks to Geoff for his comment, eye-opener to me (boom boom), noting value is discussed extensively in this book. But the way Geoff framed the point is very illuminating (sorry, on a roll).

"I'm on my second attempt to read the book. It's not a light read. By the end of a day's work from home, my mind is usually numb / mush. I need something lighter to 'distract' my mind and give it a chance to defrag from work, before tackling something else of substance. I no longer have the commute home, during which time I would usually peruse my favoured photography sites and the news—not that I'm saying TOP is lightweight.  ;~)

"I'll stop there before I dig myself in any deeper."

Mike replies: No offense taken. TOP is not lightweight enough. I'd get more readers if it were more so.

Will: "The Gird Isiollun msot rmednis me of the wlel konwn fcat taht msot rdaeres hvae no dltfifiucy raindeg a ppgararah of txet wtih asbrud sllepnig as lnog as the fsirt and lsat ltreets are crerctloy paelced. The brain is a fascinating machine indeed!"

Comments

[Richard Parkin]

Curious! I assume you are not colour blind like me (red-green) but my experience is close to yours. I too bought one of the last B&O Monochrome TVs and used it long after colour TV arrived. It was also superior for displaying older B&W movies of course which may have been a factor. I never learnt the names of a lot of colours though it didn’t bother me and only found I was colour blind when tested for National Service (Draft?).

[Jeff Nesheim]

I am quite colorblind, and the way you describe luminance vs chroma is a great way to put it. B&W photos have *so much more* information (to me) than color photos, which are mostly brown and gray, with a splash of blue or yellow (I assume?) here and there, like my real world. I've always shot 90% B&W as a result, with the 10% color relying completely on camera/PP to decide what's right.

In this particular example, the girl with the turtle seems to have a yellow shirt. Most everything else is B&W, with a little brown (the 'headless' boy's shirt?). Thanks, this is already in my 'examples that help me understand color' file!

[John Merlin Williams]

It's worth noting that the ability to preview the image in B&W is a very new phenomena, circa the early 2000s, via the digital screen/viewfinder. So even the greatest B&W photos before the 21st century were visualized on a ground glass, a focusing screen, or through an optical viewfinder/rangefinder - even the "no glass" sport finder frame - all in color. Assertions that using a monochrome-only system is somehow an advantage should be considered in light of that history.

I too, can't not see in color and find using a B&W preview distracting. BUT, for me, the ability to apply filters in post-processing creates the ability to produce the relative luminance values I perceived in the natural color scene.

My personal project is BTS motorsports, where motorcycles, team liveries and pit furnishings are a riot of contrasting, bold colors. I often find that using a software filter (reminiscent of using a deep red filter with B&W film to render a deep blue sky as we perceived it) can restore some differentiation in luminance between a deep red and black, or a green and blue livery. For me, it's been a huge help in my attempts to use B&W final images to emphasize the personal character of participants, in a genre dominated by color images and action scenes.

[Rube]

Being red-green color blind makes me unqualified to comment on this. Few people like any of my colored shots (much too vidid, too bright, too colorful, too unrealistic) but they look subdued to me. The lesson is, if there is one, is that we all tend to see color differently.

Rube

[Roger Bradbury]

I have perfect colour vision, but the grid illusion hardly worked at all for me. The tree between the two girl's heads on the top far left corner seems to be green, but I think that's because all I can see is a mixture of green lines, dark shadow, and maybe a bit of white. The blue grid lines almost work.

[Craig Beyers]

My photographic eye tends to be dominated by shapes, lines, light and shadows, and movement, so I tend to see in monochrome. Some subjects that I photograph are more aptly defined by their color elements—hue, saturation, etc.—rather than shape, lines, etc. So, like Ctein, I easily switch between monochrome and color. I mentioned this in a conversation with a fine art photographer friend. She indicated she’s the reverse: she’s sees the color elements first, then shapes, lines, etc. Her work is dominated by color, while my non-sports work is dominated by, yup, shapes, lines,, etc. Sports, for the most part, is dominated by the moment and the story, where teh action is the most important element and color, shapes, lines, etc. are secondary. However, I can’t image using a B&W-only camera as color often is important and I’d hate to miss a color photograph while limited to B&W.

[Peter Williams]

Bob Keefer's comment is fascinating. I'd love to see examples. I'm quite willing to believe, but it's rather counterintuitive.

[Terry Letton]

This is interesting, when I first looked at the picture on my old (6) iPhone I could see the illusion, but as some as I expanded the picture even just a little bit all I could see was the lines. I guess once you are onto the trick it doesn’t work anymore, at least for me. My increased visual acuity after recent cataract surgery may be a contributing factor, I know it has changed my perception of certain colors to the extent that certain digital black and whites that I added sepia toning to will have to be revisited as the color is wacky

[Bear.]

The way the mind works is quite fascinating. Glancing at the grid photo, it look like colour - but if I concentrate hard on the colour perception and the grid, I can see the coloured grid with the grey scale photo behind, until I lose concentration. It's rather like looking at an Escher illusion.

I've never had a mono only camera. But I did shoot exclusively B&W film for years and only moved to colour after the advent of digital. IMHO the issue is not the monochrome output of the sensor but the photographer's perception of the input through the viewfinder - after all, whether shooting rangefinders or SLRs on film, I always saw the world in colour and internally visualised the B&W output. I have tried switching mirrorless viewfinders to B&W to shoot to that output and dislike the sensation because I am just bypassing the internalised artistic sensations. But I also find it very difficult to switch at will between OVF and EVF because the former is simply a scaled version of the real 3 -dimensional world as perceived by my eyes, whereas the latter presents as a prepared 2-dimensional image removing the necessary internalised process of converting what I see into the output image. Having said that, I finally went for it and bought a Leica Q2 which has a much better EVF than the much older lower resolution mirrorless EVFs I had previously used and have had far less difficulty because of the 3-dimensional presentation of the image on the screen. I am very interested to try a Sony A1 with its 8k plus EVF to see whether it's better yet.

[Cliff McMann]

Interesting Mike! Thanks for posting this. Like you, I found the Red grid ruined the illusion. I have a coworker who seems addicted to mixed color text in his emails (shudder.) i have noticed that I perceive the color of the text as distance differences, the red text appears as if it floats above the black background (I run dark mode, a black background on my Mac) and the other colored texts appear to me to be a different size font. I’ve assumed this is because different wave lengths are shorter. Possibly the delta in wavelength between colors affects my minds perception of the distance with the high percentage change from Red to yellow creating an interpretation of a greater distance? I really enjoy being shown how faulty my unshakable view of the world is!

[darlene]

I immediately see red grid patterns most everywhere, then green and yellow grids. At the start of my career, art directors said it was what I do with color they liked. So I do not know what to make of this.

[Colin Dixon]

Colour is everything, black and white is, simply, more!

[James Sinks]

There's another kind of grid illusion that can pop up naturally in certain circumstances--when you have a black grid against a light background, light colored dots can scintillate in and out of existence at the intersections of the lines. It's really neat, but also incredibly alarming when your discover it for yourself while editing a photo and start googling for neurological symptoms...

I have a couple examples in my portfolio, but these two are my favorites (best full screen, so no embedded preview, sorry):

http://cloudfront.dementlieu.com/forfriends/sinks_grid_illusion_5262b.jpg

http://cloudfront.dementlieu.com/forfriends/sinks_grid_illusion_4287.jpg

And now I have to print these guys and see how the illusion works with reflective images.

[Richard Parkin]

FWIW I am definitely colourblind but I see the photo in colours but with red or green or yellow or blue grids over the coloured clothing and skin. The only parts with no grids are the white T-shirt and sleeve and some shoes.

[Rob de Loe]

I've had a brangle or two with the people who say that you can't do black and white photography properly, with sufficient dedication, etc., unless you shoot a monochrome sensor. Or should I say a Monochrom sensor...

I think that's nonsense -- or more charitably, I think that's a strong personal preference mixed with a large dose of confirmation bias.

As John Merlin Williams correctly points out, people who shot black and white film back in the day were looking at colour scenes (unless they simply couldn't function without one of those monochrome viewers).

What I saw on my ground glass was a colour scene. To this day I'm still not very adept at knowing exactly how a colour will appear as a gray tone. The fact that it can be nearly any tone I want thanks to RAW data and Lightroom hasn't given me an incentive to get better. What's more important to me is that when I shoot for black and white, it's not the "colour > tone" relationship that is driving me; it's shape, line, luminosity, pattern, texture I'm watching out for. Of course "colour > tone" matters; but I mostly find it in the necessary corner, rather than the sufficient corner.

What I am extremely good at now is knowing when it's not worth pressing the shutter because what I'm seeing is actually a colour picture. It's not complicated, and you actually outlined the rule above: "actively use color as a primary creative element in their photographs". If the picture I'm seeing only works because of colour, then it's not a black and white photo.