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Hi there everyone,
I have a question about light and color. It's very simple, I'm sure, but for me, I'm struggling. I paint in Photoshop and use the 'H' or 'Hue' color picker orientation when I'm choosing colors. Essentially, I know that white light carries all of the colors of the spectrum, and that when it strikes an object, the atomic structure of that object causes the wavelength of white light to vibrate in a different way. For this reason, objects appear red or blue or green (and so forth).
I think I'm fine with that part of the 'theory', but I get confused when trying to pick colors in photoshop for when I'm emulating white light in a painting. Look at this image:
I've drawn a vertical line next to the color selector. Essentially, if I have a 'red object' (I know that color isn't inherent in objects, but let's just call it a 'red object' for sake of simplicity), and I'm lighting the object under completely white light, will the resulting situation be such that I'll have to select colors in a perfect vertical line when using the 'H' or 'Hue' setting in Photoshop? To me, it looks like they have black mixing at the bottom of the square (color square) and that brightness is what the vertical line controls.
I'm just curious, because I can't seem to find any manuals or information on this specific question. I'm sure the data is out there, but it's hard to specifically search for this kind of answer.
Also, am I right in saying that, when less light is involved, that we push down on the vertical line towards black? Essentially, light in the form of a photon and wavelength (for an individual photon) is reaching the eye and the photon isn't strong enough to light up a complete 'patch' of the vision plane (I'm guessing that human vision is a 2Dimensional experience, in that, 'vision' resides in the second dimension -- could be wrong -- please correct me otherwise). This results in mixing with the black of 'non-vision'. Henceforth, when we want to emulate less light hitting a structure (less powerful photons), we just move down on the vertical line (on the color square) and, voila, we have less light.
Of course, this is all in a vacuum with no atmosphere or atmospheric effects like Rayleigh scattering, etc. I just want to get down what happens in the 'vacuum' before starting to emulate blue light from the sky, as well as other bounced light.
Thank you so much for your input and time...
Listen to your uncle Eezaq! He knows of what he speaks.
Unless you're going for some kind of monochrome effect you want to actually use different colors to paint with. Pure white light is pretty rare, the sun is yellow or orange or red depending on time of day and atmospheric conditions, and artificial light sources all tend toward some color tint or other. Then you also need to take into account the prevailing color of the surroundings - walls or foliage or dirt or whatever the environment dictates. White light in a green room will bounce around a lot and give a very greenish illumination, the sky provides a lot of blue fill etc.
What you're describing is monochromatic. Sliding the cursor up or down adjusts only value of the color. If I'm modifying a color using the picker I also like to push the cursor to one side or the other (to change saturation), and then also adjust the hue (the vertical slider to the right of the color picker square).
I like to use a strategy called spectral shift, in which as a color gets lighter or darker it shifts along the color spectrum too… for example a red will turn more orange as it lightens (a good way to avoid having to use pink) and more purple as it darkens.
If you want to learn painting you definitely need to study color theory - get a lot of books.
Thank you very much for the kind and thoughtful reply, Darkstrider.
I am aware that this is basically a question of, as you put it, monochrome. I was thinking of, say, a sphere or planet in space without an atmosphere. The viewer is out in space and we have a star lighting the planet. Would a star emit pure white light and, if it hit the (say, 'red') planet, would we simply move up and down on a vertical line that I represented in my demonstration image (depending on how saturated the planet was or how 'creamy-colored' the planet was, the vertical line would be placed appropriately)?
Of course, we'd have to incorporate atmospheric perspective into the way we calculated how 'red' we painted the planet (for example, earth appears as a pale blue dot at the edge of our solar system), but I think you get what I'm asking.
This leads to a question about the 'yellow' sun. The yellow appearance and effect of sunlight is just because of the angle of entry into the atmosphere and the way that atmospheric gases cause the wavelengths of light to change, correct? This is why we have varied and colored sunsets -- because of the angle of entry -- of photons into the atmosphere -- and their interactions with gases, dust, etc.
Thank you for the tip on the 'spectral shift', as well. I've painted a few concept paintings, but never took the spectral shift into consideration. They came out okay, but I'm always searching for more realistic results.
Essentially, I am just being very exact in this post -- I want to know if there is any 'vacuum-like' situation where we would have the color travel on this kind of vertical line. Also, I suppose any information about the quality of light from stars would be helpful, too. Is it pure white (all of the colors of the spectrum) in reality?
Nothing at all wrong with your question, gillianseed! The vertical line shows a set of colours in which Photoshop Hue and Saturation remain constant and only Brightness changes, so yes, it does give a series of image colours suitable to represent an object of one colour turning out of a single light source, underlying any other complicating factors. I've referred to this kind of series of colours as a shading series on this page:
In a hue-value-chroma space these lines radiate from the black point, increasing steadily in chroma as they increase in value. The specular reflection however generally retains the colour of the light source and so is not on this series.
It sounds like you're a lot more scientific and precise about things than I tend to be - I'm not sure how realistic a spectral shift is, but it looks really cool! And I'm more concerned with that than with absolute accuracy. But then I guess I'm generally more concerned with aesthetics than accuracy, except in things like anatomy and perspective (even there I'll freely fudge it if it looks ok or if accuracy makes it look unappealing).
Some stars do seem to emit a pretty pure white light, though some seem to be red or yellow or blue. So sure, you could have a white star. And of course there's no atmospheric perspective in space either, the only atmosphere would be the paper-thin layer on the surface of the planet if it has one. Things in space tend to look clear and have a hard light on them that gives very crisp shadows and no fill light unless there's some other celestial body positioned to reflect onto it. But then of course there's artistic license - you can go ahead and put some bounce light if you want, say maybe there's a planet or star just offscreen that you can't see in the image or something.
I guess it would depend on the type of image you're doing. If it's supposed to look scientifically accurate or like a hard sci-fi cover, then I think a monochrome red planet might work, but personally I would tend toward something more aesthetically pleasing, which to me means some nice juicy colors. I'd do it more like a Frazetta planet than a Bonestall planet lol! Your choices may vary.
Last edited by Darkstrider; June 20th, 2014 at 01:20 AM.
Perspective is actually a good analogy. Just as lines in an image that converge on a vanishing point will appear to be parallel lines moving away from you, image colour series that converge on black will appear to be uniform surface colours passing into lower light. It's useful to know that whatever you paint with, even if you don't always paint things that way.
Darkstrider, thank you again for the useful comment.
briggsy@ashtons, thank you for the very useful comments, along with the images to study. I'll be studying your great website today and many days in the future.
arenhaus, thank you for the book recommendation. I actually already have that book, but haven't spent enough time in it. I'll do as you said, although, I really don't like physical painting all that much. I prefer digital painting, but if anyone can explain the real benefit to physical painting, I'll give it some time. For example, I took several painting classes in college and never really enjoyed it as much as I enjoy digital. I don't like the mess it makes and I didn't like having to get set up every time with the easel, paints, etc.
I've always wondered about this though. Two people have said that in this forum thread already -- 'directly paint'. This, for example, is something I painted in Photoshop. No mess and endless ways of adjusting things to my liking.
Granted, I am not AT ALL saying that physical painting is inferior. I'm just saying that I really enjoy digital as opposed to physical painting.
Looks like you need to learn more than just colour. There are anatomy and value problems in that picture. The reason why real painting is preferred for learning is because you have to learn and not take short cuts.
I didn't come here to get belittled and talked down to, Black Spot. If you have nothing nice to say or if you can't say it nicely, I'd prefer you to keep it to yourself.
Thank you for the kind words, from those that cared. For the nasties on here, no thanks to you.
Good day to the kind ones.
Last edited by dpaint; June 20th, 2014 at 02:42 PM.
Kindness isn't the important part of someone's response, truthfulness is, and making it understandable and helpful - the kindness is just the spoonful of sugar that helps the medicine go down. The hurt feelings will go away in a while, but the actual advice is lasting and powerful. And trust me, tough love is a lot easier to take online than in a classroom full of people where everybody can see if you get upset or mad. Especially if you were up all night slamming pots of coffee to try to get a piece done in time for critique session and drag your ass in all sleep deprived and just wanting nothing more than to crash out (trust me on that one).
But what picture is everyone talking about? OP didn't post one, aside from the color picker. Unless you're talking about another thread?
Ok, gotcha Black Spot- it's there now.
That said, I'm using photoshop to learn about painting. I spent many years trying to paint in various traditional media and wasn't making much progress, but I've been able to make some good headway in photoshop. However, I'm being careful to mostly avoid the gimmicks and tricks and just use it as a basic painting program. I'd be interested in hearing what the more experienced people around here think of that. I suspect I'm doing alright largely because I did use traditional media for a long time first, and had a pretty solid grounding in drawing, including full value rendering in pencil. I think if I would have started right in with photoshop I wouldn't have understood much about the basics of painting and instead would have had a field day playing around with gimmicks and not learned much properly.
Before moving on to color you should learn to control shapes, values and edges - Level Up is good for this (even just the freebie parts of it). Work in black and white in the beginning until you can do all of this. Then you can start to bing in color, monochromatically at first, then 2 colors, then 3. At least this is advice I've seen in several books o painting that were published prior to the 50's or based on good solid traditional training from before the 50's (when modernism and postmodernism started infecting everything and it became all about "Just paint what you feel!"). Learn to juggle one ball, then bring in more one at a time.
Last edited by Darkstrider; June 20th, 2014 at 04:36 PM.
Real paint is better than digital for the simple reason of forcing you to plan what you are doing. It is too easy to pfutz with Photoshop forever, blindly, because the cost of lack of planning is low and blending / fixing is too easy. But with real paint, you have to THINK first.
In short, limitations are good in this case.
I actually think there's some benefits to digital as a learning medium, while acknowledging all the negatives you guys pointed out. But I do think it's best for people to be able to draw well in pencil or charcoal or something, including full shading and knowing how to make things look 3 dimensional, before messing with color or probably digital painting.
It might be a good idea to move back and forth between traditional and digital - photoshop really does make it a lot easier to learn certain things that might be total roadblocks if you're going hardcore traditional. But it's also important that people know to avoid all the gimmicks and use photoshop like a basic painting simulator as much as possible.