Page 1 of 2 1 2 LastLast
Results 1 to 13 of 19
  1. #1
    Join Date
    Jun 2014
    Posts
    4
    Thanks
    4
    Thanked 0 Times in 0 Posts

    Rookie Question about Color and Light

    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:

    Name:  lightquestion01.jpg
Views: 245
Size:  247.1 KB

    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...

    Reply With Quote Reply With Quote


  2. Hide this ad by registering as a member
  3. #2
    Join Date
    Jun 2007
    Location
    Toronto, Ontario
    Posts
    1,625
    Thanks
    21
    Thanked 538 Times in 385 Posts
    Quote Originally Posted by gillianseed View Post
    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:
    This is exactly why you better study the basics of painting with traditional media, focussing on what you see, without getting caught up in the intricacies of Photoshop...

    Grinnikend door het leven...
    Reply With Quote Reply With Quote

  4. The Following 2 Users Say Thank You to eezacque For This Useful Post:


  5. #3
    Join Date
    Apr 2004
    Posts
    1,336
    Thanks
    145
    Thanked 321 Times in 271 Posts
    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.

    "Figure drawing prepares you for painting at a high level" - Jeff Watts

    Sketchbook
    Reply With Quote Reply With Quote

  6. The Following 2 Users Say Thank You to Darkstrider For This Useful Post:


  7. #4
    Join Date
    Jun 2014
    Posts
    4
    Thanks
    4
    Thanked 0 Times in 0 Posts
    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?

    Reply With Quote Reply With Quote

  8. #5
    Join Date
    May 2005
    Location
    Sydney
    Posts
    853
    Thanks
    192
    Thanked 1,395 Times in 336 Posts
    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:

    http://www.huevaluechroma.com/101.php

    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.

    Name:  10-1.png
Views: 146
Size:  62.5 KB

    Reply With Quote Reply With Quote

  9. The Following 2 Users Say Thank You to briggsy@ashtons For This Useful Post:


  10. #6
    Join Date
    Apr 2004
    Posts
    1,336
    Thanks
    145
    Thanked 321 Times in 271 Posts
    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.
    "Figure drawing prepares you for painting at a high level" - Jeff Watts

    Sketchbook
    Reply With Quote Reply With Quote

  11. The Following User Says Thank You to Darkstrider For This Useful Post:


  12. #7
    Join Date
    Jan 2010
    Location
    Haifa, Israel
    Posts
    4,485
    Thanks
    2,462
    Thanked 2,499 Times in 1,548 Posts
    "Color and Light" by James Gurney. Get it and read it.

    Practice with real paint, not Photoshop.

    Reply With Quote Reply With Quote

  13. The Following User Says Thank You to arenhaus For This Useful Post:


  14. #8
    Join Date
    May 2005
    Location
    Sydney
    Posts
    853
    Thanks
    192
    Thanked 1,395 Times in 336 Posts
    Quote Originally Posted by Darkstrider View Post
    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).
    Sounds just right to me - you're not bound by anatomy or perspective, but you do understand them.

    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.

    Name:  2.22 Saturation series.jpg
Views: 142
Size:  34.6 KB

    Reply With Quote Reply With Quote

  15. The Following 2 Users Say Thank You to briggsy@ashtons For This Useful Post:


  16. #9
    Join Date
    Jun 2014
    Posts
    4
    Thanks
    4
    Thanked 0 Times in 0 Posts
    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.

    Name:  NativesDownsized.jpg
Views: 129
Size:  591.7 KB

    Attached Images Attached Images  
    Reply With Quote Reply With Quote

  17. #10
    Join Date
    May 2008
    Location
    London
    Posts
    11,365
    Thanks
    3,785
    Thanked 5,838 Times in 3,944 Posts
    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.

    Reply With Quote Reply With Quote

  18. #11
    Join Date
    Jun 2014
    Posts
    4
    Thanks
    4
    Thanked 0 Times in 0 Posts
    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.

    Reply With Quote Reply With Quote

  19. #12
    Join Date
    Sep 2009
    Location
    Virginia
    Posts
    4,978
    Thanks
    2,826
    Thanked 6,088 Times in 2,481 Posts
    Quote Originally Posted by gillianseed View Post
    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.
    Grow up. There is nothing nasty in her comment. If you can't take honest criticism from people who know more than you do you won't get anywhere in art. Color is not isolated from value or anything else in painting and her comments are spot on. No one has time to molly coddle you.

    Last edited by dpaint; June 20th, 2014 at 02:42 PM.
    Reply With Quote Reply With Quote

  20. The Following User Says Thank You to dpaint For This Useful Post:


  21. #13
    Join Date
    Apr 2004
    Posts
    1,336
    Thanks
    145
    Thanked 321 Times in 271 Posts
    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?

    "Figure drawing prepares you for painting at a high level" - Jeff Watts

    Sketchbook
    Reply With Quote Reply With Quote

  22. The Following User Says Thank You to Darkstrider For This Useful Post:


Page 1 of 2 1 2 LastLast

Members who have read this thread: 0

There are no members to list at the moment.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
  • 424,149 Artists
  • 3,599,276 Artist Posts
  • 32,941 Sketchbooks
  • 54 New Art Jobs
Art Workshop Discount Inside
Register

Developed Actively by vBSocial.com
SpringOfSea's Sketchbook