ISO -- What is it? Lol..

Discussion in 'Photography Beginners' Forum' started by RKW3, May 21, 2007.

  1. RKW3

    RKW3 TPF Noob!

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    Yeah what is ISO again? I'm a 14 year old kid that just gotta camera, be EZ.

    It's probably something I know, or maybe not..


    SIMPLE QUESTION, SIMPLE ANSWER. THANKS.
     
  2. deadtoaster2

    deadtoaster2 TPF Noob!

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    Its the measure of your film (or digital medias) sensitivity to light. The lower the number, the longer the exposure will be needed to take the same image with a higher iso.

    See http://en.wikipedia.org/wiki/ISO_(photography) for more info.
     
  3. EOS_JD

    EOS_JD TPF Noob!

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    "Understanding Exposure" by Bryan Perterson will help you......

    He likens ISO to worker bees collecting light. If you double the number you half the time to do the job (exposure time). As above it's the sensor's/film's sensitivity to light. THe higher the number the more sensitive, the less light required to get a correct exposure.

    Down side is that the higher you go, the more noise/grain you will add so IQ drops.
     
  4. Alex_B

    Alex_B No longer a newbie, moving up!

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    I suppose IQ means image quality?

    yep, ISO as a measure for the sensitivity to light is probably the easiest wording.

    double the ISO and you need half the amount for light to get the same brightness on the image.

    with film, it is the chemistry which defines you the ISO, hence to switch ISO you need a different film then.

    with digital sensors it is the amplification of the signal which defines the ISO .. since this is tuneable, on digital cameras you can select the ISO easily.

    stronger amplificiation of a signal (as it is done at higher ISO) means also a stronger amplification of the noise, which hence becomes more visible then.

    with film it is the grain which is usually larger for higer ISO film.
     
  5. RacePhoto

    RacePhoto TPF Noob!

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    Actually on older cameras you will select the ASA, or maybe DIN. :lmao:

    Just adding this in case someone does bump into something older and can't find ISO. The two above are the same principles, old standards.

    It's just a standard light sensitivity value so you know how to expose the film, which has now become the sensor. Since the sensor values can change, unlike film, you can set the sensor sensitivity to many different values that replicate film ISO values.


    Read about it here. http://velatron.com/dca/ISO/
     
  6. ANDS!

    ANDS! No longer a newbie, moving up!

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    That book kicks so much ass, its not even funny.
     
  7. RKW3

    RKW3 TPF Noob!

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    Thanks for the help guys!
     

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