Human eye so much better than digital sensors

Discussion in 'Digital SLR' started by RichA, Jul 10, 2005.

  1. RichA

    RichA Guest

    The other day I shot some graffiti under a bridge.
    Half was in shadow, the other half in bright sunlight.
    There were 6 stops difference in exposure between them.
    Once I saw the images, I knew it would be very difficult
    to produce an acceptable or even marginally exceptable final
    image. But what I did notice was that my eyes had no trouble
    seeing both sides of the graffiti whereas the digital camera
    just did not have the dynamic range to accommodate it properly.
    I'm wondering what they'll come up with to finally (if possible)
    deal with this problem. I'm beginning to really love overcast days.
    RichA, Jul 10, 2005
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  2. RichA

    Bubbabob Guest

    Take two or three shots 2 stops apart and composite them with the new 32
    bit compositing feature of PS CS2. Works great.
    Bubbabob, Jul 10, 2005
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  3. RichA

    RichA Guest

    I may have been overstating the case. I'll try your suggestion as
    well. But, after fooling with the histogram function, I managed to
    get the image to a point that approximated how my eye saw it.
    RichA, Jul 10, 2005
  4. RichA

    Rudy Benner Guest

    "32-bit High Dynamic Range (HDR)—Step into the future, with the creation and
    editing of 32-bit color, High Dynamic Range (HDR) images, ideal for 3D
    rendering, advanced compositing and professional photography. With advanced
    technology that adapts to the full spectrum and range of visible light in
    the same way as the human eye, HDR ensures your final images will display
    your creative vision to the last detail, with the most richly detailed
    shadows and highlights at your command. Let the new Merge to HDR take you
    beyond the state-of-the-art, by automatically combining bracketed digital
    exposures into a single 32-bit HDR image, creating breathtaking images that
    are otherwise impossible to capture with traditional cameras."
    Rudy Benner, Jul 10, 2005
  5. RichA

    Rudy Benner Guest

    Look for it in Bridge. I could not find the function in Photoshop. Seems to
    work. This could be fun.
    Rudy Benner, Jul 10, 2005
  6. Welcome to the world of photography. It was no difference in the days
    of film.
    Randall Ainsworth, Jul 10, 2005
  7. Well, slightly. You can to some extent control the contrast ratio of
    film by controlling development time (or first dev time for colour
    film). Works well for B&W film, works to a lesser extent for E6
    (reversal) film, is barely possible with C41 (negative) film as the
    process is usually so rigidly automated.

    It would sometimes be nice to have sensors with variable contrast,
    though to be fair they do start out with a higher range than most films,
    and the techniques already mentioned serve instead.

    David Littlewood, Jul 11, 2005
  8. RichA

    Jeremy Nixon Guest

    Your eyes don't take a picture; they piece the scene together from multiple
    "samples", plus memory, and present it to you that way. You can, of course,
    do the same thing in Photoshop. :) (Well, minus the memory part.)

    Have you ever had this happen to you: you're on a dark street at night,
    with some street lights and lights from houses around. Way down the street
    you see something, but you're not sure what it is. You think it might be a
    person. Or an animal? Or... something in the road? You look at it, move
    your head, look again, maybe walk to get a slightly different angle and
    look again; finally, you suddenly identify it as a car parked on the side
    of the road. Your brain finally got enough visual information to piece
    together into that.

    Now, every time you look at it, whether you look away or not, all you can
    see is a car parked on the side of the road. Whatever you initially may
    have thought it could be is gone, and you can't even see how you ever
    thought that, even if you return to your original vantage point. You're
    still seeing the same thing you saw before, but now your brain is filling
    in the missing pieces and you see a car.

    Your camera can't do that.
    Jeremy Nixon, Jul 11, 2005
  9. RichA

    Chrlz Guest

    now your brain is filling in the missing pieces
    Exactly. And in terms of not only exposure, but also resolution. Your
    eye/brain has got a *lot* less in common with a camera than most folk
    think. Go back to that graffiti site, and stare fixedly at one part of
    the scene. While you remain staring fixedly at that point, can you
    actually read something, or truly see *new* detail, in the other
    brighter/darker areas outside those couple of degrees that are in sharp
    focus and correctly 'exposed'? Try it right now, focus on this little


    Can you genuinely read anything 3 lines above or below? Can you
    *really* see detail in bright or dark areas in the rest of your field
    of view? The rest of your view is of much lower resolution, and while
    your eye is adjusted for an area of one brightness it cannot adjust for
    other areas. So the *brain* takes over and fills in memorised or
    'fake' detail, or increases/reduces your perceived 'exposure' of the
    other areas outside that narrow tunnel. It is only when your eye
    moves, and then the pupil dilates/shrinks, that it can cope with the
    dynamic range of the scene. In other words... it cheats!

    The camera, of course, has to try to capture everything in the scene
    all at once (so that your eye can wander over the final image and cheat
    again!). So IMO, the eye isn't so much 'better', it's just
    *completely* different..
    Chrlz, Jul 11, 2005
  10. How do you know he shoots Nikon and not Canon?


    Instead of compositing in Photoshop, you might be able to pull out the
    shadow contrast with some simple Levels adjustment.
    Steve Cutchen, Jul 11, 2005
    Andrew Koenig, Jul 13, 2005
  12. RichA

    RichA Guest

    RichA, Jul 13, 2005
  13. RichA

    Todd H. Guest

    Read the subject and just couldn't resist the urge to respond "Well no
    shit, Sherlock."

    The human eye's sensitivity to dynamic range with visible light has
    always elipsed the livin crap out of any recording medium consumers
    have ever had remotely economical access to (be it reasonably sized
    print film, slide film, or digital sensors).

    Half of the technical aspect of photography involved figuring out how
    to work around the medium's limitations and dynamic range.

    Best Regards,
    Todd H., Jul 13, 2005
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