A&P How important is using 'natural' light?

Discussion in 'Lifestyle' started by BitchThatEatsOnions, Aug 9, 2005.

  1. BitchThatEatsOnions

    BitchThatEatsOnions New Member

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    I have no idea what I am doing as far as photography is concerned. I just bought my first real camera (Rebel XT, Tamron 28mm-75mm, Canon 50mm) along with a tripod etc etc. How important is shooting in 'natural' ie sunlight to getting good color saturation etc. It seems that when I shoot indoors with the lights on that everything has a yellow hue to it. Is that just because the standard incandescent bulbs are having their offwhite color amplified because the shutter speed is slowed due to having less light? TIA

    Any recommendations on lighting that I can get for "product" shots? What about car pics at night...do you have to find a place with HID lighting (the white kind not that mercury (?) yellow/green crap) to take good shots?
     
  2. eof

    eof New Member

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    hmm...your white balance is off if you have any tint. Shoot in raw and fix in photoshop or just get it right on the camera. I have never had this problem with my D70...the auto white balance is pretty much dead on. :dunno:
     
  3. BitchThatEatsOnions

    BitchThatEatsOnions New Member

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    So I can shoot with crappy incandescent light and have it come out 'white' in the pictures by adjusting the white balance...?
     
  4. eof

    eof New Member

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    No question...that is the point of white balance.
     
  5. eof

    eof New Member

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  6. hash browns

    hash browns lolcathlon champion OT Supporter

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    Tungsten / Incandescent lighting is generally extremely biased towards yellow when we're talking about colors separated into R-G-B channels. Yellow and blue are related in color balance, where more yellow means less blue.

    Most digital imagers use a Bayer-type grid array, biased towards the green channel -- green most frequently occurs in nature -- and less so with Red and Blue. Thus the signal quality in the blue channel tends to be less, by a stop or more, than the green channel.

    Cliffs: Regular tungsten -> too much yellow, less blue, yadda yadda not as good as daylight or daylight balanced bulbs
     
  7. BitchThatEatsOnions

    BitchThatEatsOnions New Member

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  8. deusexaethera

    deusexaethera OT Supporter

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    Using full-spectrum lighting is far more important than using "natural" lighting. The reason for this is complicated, but bear with me:

    Fluorescent lights use between four and eight types of coatings inside the tube to convert the ultraviolet light being produced into visible light. This means that you only get between four and eight colors of light, which you can see if you look at the reflection of the light tube on the shiny side of a CD (a regular light bulb makes a rainbow smear instead). The rest of the spectrum is black. Streetlights do something similar, and the detailed differences between the two are not important right now.

    The reason why you don't notice that there are only 4-8 colors of light is because your eyes (or the camera's light sensor) have three kinds of receptors -- red, green and blue -- which are sensitive to different shades of each color in differing amounts. As a result, your brain (or the camera's CPU) still think they're seeing natural light.

    The problem with this is that the 4-8 colors of light from a fluorecent tube do not reflect off objects the same way full-spectrum light does; instead of being guaranteed to have at least a few shades of the spectrum reflecting brightly, you only have a couple of the 4-8 colors managing to reflect AT ALL. (in the case of "white" streetlights, there is no red light at all, and red objects come out looking black.) This causes your eyes (and the camera) to percieve a different mix of colored reflections than you would if you had a full-spectrum light.

    In short: fluorescent lights and metal-gas lights (streetlamps) do not reflect properly, so objects look like they're different-colored than they really are. Full-spectrum lights don't have this problem, because they produce at least a little of every possible color of light.

    How can you tell if a light is a full-spectrum light? Easy. If it makes light by getting hot, it's full-spectrum. Tungsten lightbulbs (even the tinted ones), halogen lightbulbs, and the Sun fall into this category. Metal-gas lightbulbs DO get hot, but the metal-gasses inside them do the same thing as the coatings in fluorescent bulbs, so they're not suitable for good photography.
     

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