03-14-2015, 10:57 PM
This is where designing your illustration around light and shadow is super important. Everything you just showed is completely perceptual; we KNOW that shirt is black and that paper is white, or that checker is black and that checker is white, because we have 2 different sets of information: we have a part of it in light, and a part of in shadow. Despite the fact that they are the exact same value, and sometimes even the same colour, our brain/eye will still make adjustments so it reads properly and so that we understand the local value of and thus can separate it from the information around it. If he had set up those pictures in a different way, for instance removing the gradient in the background of the shirt picture, or setting things up so you dont see the light side of the newspaper, the illusion would vanish or be severely reduced. Because we have the light information, ie we know that under light the newspaper is extremely light and because we see the transition between light and shadow clearly instead of it being obstructed, it's much easier for our brain to make the leap that that is, in fact, white.
Also, the problem with his example is twofold
1: that shirt is not 100% matte like the paper is, therefore it reflects more light and despite being black it appears quite light. If he was a wearing a black cotton tshirt under sunlight the 1/2 way to black rule would be much more apparent, and the illusion we create to understand local value would still be present but much less drastic than this.
2:Black generally speaking is more blueish, especially in this scenario it seems as though its not pure black but quite a bit more saturated than the paper by comparison, while white, especially under sunlight, is more yellow-orangish, therefore not only is there value contrast going on, but also complementary contrast. So even though it seems black and white, it's emphatically not, though the difference is quite subtle. People always say you can't turn form or create separation with colour, but that is just simply not true. The effect is much more subtle, but its possible and often necessary to do so especially when you have situations like this.
I took a cross section of two different segments to show what I mean. The picture was quite low res though so its blurry but it shows my point about surrounding value/colour
![[Image: 357hyyp.jpg]](http://i58.tinypic.com/357hyyp.jpg)
The two samples were taken right around where he put the number. I also used clone stamp to remove some of white that was creating a separation of light and dark between the paper and shirt. Notice how in both cases the illusion seems less intense, and when you observe the colours in grayscale with Dot gain, you see how close they are in value. Some of the illusion was clearly due to complementary contrast, some to simultaneous contrast, and much, much less to value contrast.
So in conclusion, if you want white to read as a white in the shadows despite it being darker than black in light, you must organize your light in such a way that we know in light that it is in fact white, and you must organize your colour in such a way that there is separation there as well. There's no formula like 1/2 to black, its very much situational. Also it's good to want to understand the subject, if thats the way you are don't fight it, just seek answers and experiment with them until you feel you have some understanding of it. It will help later on, not because you will be able to recite it perfectly or need to plan exactly every single contingency in a painting, but you will be able to resolve issues surrounding the design of colour and light in your work intuitively. If you're stressing over it in these exercises and studies thats a good thing, it's better than being faced with a deadline and running into then because you always brushed it off while studying. My sensei used to tell me "Bleed and sweat in the dojo so you don't have to in the battlefield". I think that's an apt way to put it here
Also, the problem with his example is twofold
1: that shirt is not 100% matte like the paper is, therefore it reflects more light and despite being black it appears quite light. If he was a wearing a black cotton tshirt under sunlight the 1/2 way to black rule would be much more apparent, and the illusion we create to understand local value would still be present but much less drastic than this.
2:Black generally speaking is more blueish, especially in this scenario it seems as though its not pure black but quite a bit more saturated than the paper by comparison, while white, especially under sunlight, is more yellow-orangish, therefore not only is there value contrast going on, but also complementary contrast. So even though it seems black and white, it's emphatically not, though the difference is quite subtle. People always say you can't turn form or create separation with colour, but that is just simply not true. The effect is much more subtle, but its possible and often necessary to do so especially when you have situations like this.
I took a cross section of two different segments to show what I mean. The picture was quite low res though so its blurry but it shows my point about surrounding value/colour
The two samples were taken right around where he put the number. I also used clone stamp to remove some of white that was creating a separation of light and dark between the paper and shirt. Notice how in both cases the illusion seems less intense, and when you observe the colours in grayscale with Dot gain, you see how close they are in value. Some of the illusion was clearly due to complementary contrast, some to simultaneous contrast, and much, much less to value contrast.
So in conclusion, if you want white to read as a white in the shadows despite it being darker than black in light, you must organize your light in such a way that we know in light that it is in fact white, and you must organize your colour in such a way that there is separation there as well. There's no formula like 1/2 to black, its very much situational. Also it's good to want to understand the subject, if thats the way you are don't fight it, just seek answers and experiment with them until you feel you have some understanding of it. It will help later on, not because you will be able to recite it perfectly or need to plan exactly every single contingency in a painting, but you will be able to resolve issues surrounding the design of colour and light in your work intuitively. If you're stressing over it in these exercises and studies thats a good thing, it's better than being faced with a deadline and running into then because you always brushed it off while studying. My sensei used to tell me "Bleed and sweat in the dojo so you don't have to in the battlefield". I think that's an apt way to put it here