Thursday, September 18, 2008

PHOTO 101: Camera Control (ISO)

ISO 100


ISO 1600

ISO (International Organization or Standardization) can be a tricky thing. The ISO of film and digital sensors relates to the sensor or film's sensitivity to light. ISO 100 is less sensitive and ISO 1600 is more sensitive. Most people know that the higher the number, the less light is needed to capture an image. The issue with this is many people blatantly use and misuse ISO just to get the shot. With digital point-and-shoots, the camera is often set to an auto ISO feature that changes based on the lighting. Why should this be of concern? In basic terms, a photo taken at ISO 100 is much clearer than one shot at 400 or above. Raising your ISO will raise the amount of digital noise in the photo. With film, higher ISOs give more film grain. Film grain is often pretty and nostalgic, while digital noise is just plain ugly. Digital noise is most noticeable in the shadows, so I alway recommend that if you need to raise your ISO try to over expose the photo by 1/3 or 1/2 stop. Also, digital noise will not be as noticeable with a properly exposed photograph in daylight as seen in the succulent shots above (however, to the trained eye, it will still look ugly.) It only wreaks major havoc on low lit, tungsten and florescent lit photos. TIP: If you are shooting at night and you are using your on camera flash ALWAYS have your ISO set to 100 and slow your shutter speed down to 1/30 or lower to catch the ambient light in the background.


ISO 50 with correct exposure


ISO 3200 with correct exposure


ISO 3200 over exposed


ISO 3200 under exposed

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