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Thread: Color spaces, color perception & limits of the human eye

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    Color spaces, color perception & limits of the human eye

    Quote Originally Posted by Bill44 View Post
    A bit of further information. Not only, as Colin has said, are some of these colours not physically reproducible, but even if they were it is beyond the capability of the human eye to see them.
    Hmmm - a couple of deep philosophical questions ...

    - if we can't see a colour, does it actually exist?

    - if a man is speaking - and there is no woman to hear him, is he still wrong?

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    Re: Color spaces, color perception & limits of the human eye

    Quote Originally Posted by Colin Southern View Post
    Hmmm - a couple of deep philosophical questions ...

    - if we can't see a colour, does it actually exist?

    - if a man is speaking - and there is no woman to hear him, is he still wrong?
    Yes, many many colours exist that are beyond the human eye to see. They can mainly be "seen" by the measurement of their temperature or frequency. Think infrared or ultraviolet, the eye can not normally see them, but long before the colours reach these extremes the eyes ability to see them cuts out, however there are colour spaces that reach into these colours.

    The following is a really good explanation of different colour spaces and how they relate to your camera's sensor and your eye. Yes folks, your average DSLR sensor is capable of capturing colours that your eye can't see. http://www.luminous-landscape.com/tu...hoto-rgb.shtml

    For further reading search for Colour spaces, Ghost colours (eye fatigue), colour spectrum.
    Last edited by Bill44; 10th April 2009 at 03:58 AM.

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    Re: Color spaces, color perception & limits of the human eye

    Quote Originally Posted by Bill44 View Post
    Yes, many many colours exist that are beyond the human eye to see.
    Hi Bill - I hope you weren't taking me too seriously when I made that comment - I was trying to be clever (always a dangerous thing with me) by making a photographic twist on the old "does a tree falling in the forrest still make a sound if there's no one around to hear it" philosophical debate

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    Re: Color spaces, color perception & limits of the human eye

    Quote Originally Posted by Bill44 View Post
    The following is a really good explanation of different colour spaces and how they relate to your camera's sensor and your eye. Yes folks, your average DSLR sensor is capable of capturing colours that your eye can't see. http://www.luminous-landscape.com/tu...hoto-rgb.shtml
    Good article by the way. Although personally I already work almost exclusively in pro-photo / LAB, I do wonder how long it's going to be before we can print significantly outside of existing typical printer gamuts; I have to say that it's not something I personally worry much about.

    Since I do all of my own printing, I can leave all my files in large spaces and at 15 bit depths - printer does all it can - and in terms of the results "it is what it is".

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    Re: Color spaces, color perception & limits of the human eye

    Quote Originally Posted by Colin Southern View Post
    Hi Bill - I hope you weren't taking me too seriously when I made that comment - I was trying to be clever (always a dangerous thing with me) by making a photographic twist on the old "does a tree falling in the forrest still make a sound if there's no one around to hear it" philosophical debate
    Nah, not taken seriously mate. Your comments made me curious so I did further searching re the visible spectrum and I found out more than I really needed to know.

    One of the very interesting things to surface is the need for a calibration device for the Mk1 Eyeball. For a variety of reasons it seems that not everyone sees colours the same, and that (mainly due to eye sensor cone fatigue) false colours can be seen that don't actually exist in the real world. As I said, much more than I really wanted to know.


    Oh BTW, even if a woman is not present she will eventually dispute the statement.

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    Re: Color spaces, color perception & limits of the human eye

    Quote Originally Posted by Bill44 View Post
    One of the very interesting things to surface is the need for a calibration device for the Mk1 Eyeball. For a variety of reasons it seems that not everyone sees colours the same, and that (mainly due to eye sensor cone fatigue) false colours can be seen that don't actually exist in the real world.
    I've always found things like this quite interesting ... the eyes basically see "RGB colour", but the brain processes "LAB colour"; and if you stare at something with blue and green stripes for 30 seconds and then close your eyes you'll see the same pattern as an "after image", but coloured yellow and magenta.

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    Re: Color spaces, color perception & limits of the human eye

    Just to continue a bit, even if it is booring some people, during my research there was an article that said that some of the latest inkjet printers are capable of printing a wider gamut than the monitors can show. Maybe there is hope for the future.

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    Re: Color spaces, color perception & limits of the human eye

    Quote Originally Posted by Bill44 View Post
    Just to continue a bit, even if it is booring some people, during my research there was an article that said that some of the latest inkjet printers are capable of printing a wider gamut than the monitors can show. Maybe there is hope for the future.
    Hi Bill,

    This is the "essence" of sRGB -v- Adobe RGB. sRGB is more or less the lowest common denominator (so any colour that an sRGB monitor can display, an sRGB printer should be able to print and vice-versa (so slightly limited colour gamut, but no "nasty surprises" at print time.

    Adobe RGB is likely to encompass the gamuts of both monitors and printers, but - although there is a big overlap - there will be colours that are in gamut for one, and out of gamut for the other - so more capable for those who know what they're doing, and more chance of getting into trouble for those who don't.

    And then comes the likes of prophoto and LAB - with great power comes great responsibility!

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    Re: Color spaces, color perception & limits of the human eye

    Quote Originally Posted by Bill44 View Post
    One of the very interesting things to surface is the need for a calibration device for the Mk1 Eyeball. For a variety of reasons it seems that not everyone sees colours the same, and that (mainly due to eye sensor cone fatigue) false colours can be seen that don't actually exist in the real world.
    At last! A reason for not winning competitions at my local camera club.

    Tony

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    Re: Color spaces, color perception & limits of the human eye

    The Mk 1 eyeball

    It should be noted that in a lot of cases, particularly among men, the Mk 1 eyeball is defective. That is, a lot of us, probably more than 50%, are partially color blind to a lesser or greater degree. How do we factor this into a picture review.

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    Re: Color spaces, color perception & limits of the human eye

    Funny because this has been a bit of debate for me and my lab mates recently. I verge on the end that we feel colors. Our eyes are nothing but sensors/nerves just like a transistor is a sensor designed to react to a specific frequency. Yea that may seem like a 'duh' statement, but to me its a bit more. We can feel bass from music or pain from a brawl, but to realize that we 'feel' colors is a bit more. Then of course there's the PP that goes on in our brains.

    And men are always right, its just that when we know there's a woman around we choose to keep the upper hand and avoid conflict...

    So just my two cents.

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    Re: Color spaces, color perception & limits of the human eye

    Hi All - This thread prompts me to offer a couple of points about colour and vision that I should one day like to take much further. I should point out that I have studied colour for many years in many different contexts.

    The first point about colour is that we do not really "see" colour at all. Ours eyes receive electromagnetic signals ("visible light") and process those to send electrical signals (nerve impulses) to the brain. It is the brain that reconstructs those signals to afford what we call an image. Part of the image is the construct of colour. How an individual "sees" that colour in his/her mind's eye is unique to that individual. There is no way to say with certainty that I see any colour in precisely or even remotely the same way that others do. My red may be your green or purple or some other sensation that no one else can perceive. Sure, we can standardise colour spaces and swatches and names and temperatures and frequencies and so on, but none of that means we perceive the colour in the brain the same as another person. The implications of this are profound but not very well thought out at present.

    The second point I should like to make is a more fun idea. What improvements would you make to the human eye or visual system if you start from scratch and redesign it? Here are three suggestions: an extended receptor range from far infra-red to far UV; a record, recall, and pause system (that's our memory and CPU upgraded); and a Tv as well as Av facility, so that we can take long and short exposures with the eye. In fact, my suggestions model the eye more on what our best cameras can do, but there could be other facilities that we desire. Any ideas?

    Cheers

    David

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