Exposure is the way one controls the amount of light that falls on a light sensitive device such as Film or an Image Sensor. Measured in EV, or Luminance.
Controls to Know
- This controls how long light is let in.
- Measured in seconds
- Ex: 1/1000 (fast) 8′ (Very long) Aperture
- Controls the size of hte iris that lets light in.
- Measured in F-Stops.
- Ex: F 2.6 (Large opening) F 16 (Small Opening)
To properly exposure an image, photographers use light meters. There are a couple main types:
Built in Meters
Measures the ideal light for a proper exposure with even highs and lows of brightness/darkeness.
WARNING! This often averages the light for the entire photo, bad for high contrast lighting scenes.
Handheld light meters
- Measures the light in scene
- Wheel provides various camera settings to be used.
The Art of Exposure
You vary the exposure settings according to you desired effect.
What is ISO?
ISO measures the sensitivity of the film or image sensor you are using. Higher ISO’s are more sensitive to lgiht, making exposure in low light settings. Fast ISO’s are great for high light scenes or when it is a sunnday day.
NOTE: Faster ISO’s tend to increase the noice in your phtoos. Raise ISO with caution.
If you’re into landscape photos or want a shot where every detail is in focus from foreground to back, be sure to use the smallest aperture possible – this is usually means longer exposures – bring a tripod – If you want to have shallow depth of field, use a larger aperture such as f2.8.
Shutter Speed Basics:
Use a fast shutter speed to freeze fast moving objects and a slow shutter speed to blur them (you’ll need a tripod for slower speeds)!
High Dynamic Ranges
Certain scenes with both very bright and very dark areas that need to be properly exposed present a high dynamic range issue… most cameras aren’t that high tech.
Use High Dynamic Range photography, or combining multiple exposures together into one image with a wide range of light exposures.
Graduated filters also can work for High dynamic ranges by blocking out light in specific areas, like the sky in landscape photos.