- How long your cameras sensor is exposed to light.
- Measured in fractions of a second 1/30, 1/60, 1/250, 1/500
- Fast shutter reduces motion blur BUT admits less light.
- Fast shutter freezes time and uses less light.
- Slow shutter captures movement and uses more light.
- The diameter of the lens opening.
- Expressed as a fraction of focal length (f-number) f/2 on 50mm lens= 25mm aperture.
- Big f-number means stopped down aperture (small hole).
- Under exposed pictures are dark and shadows turn black.
- Over exposed pictures are white, loosing a lot of detail and there’s a loss of contrast (shadows).
- A low f-number = High aperture, smaller the ‘f’ the less light.
- A large aperture gives more light but a shallow ‘Depth of field’.
Depth of field:
- A range of distance that is acceptable ‘in focus’.
- Small = large depth of field
- Large = shallow depth of field ( background blurred) e.g. portraits.
- Image sharpness decreases away from the focal plane.
- As your aperture increases, the points in which the focal plane will produce an acceptably sharp image also increases.
- Using ‘aperture preview’ mode you can temporarily stop-down the aperture and see the true effect.
- The same exposure can obtain with a shutter interval twice as long and the aperture area half as big.
- Aperture (f/16) not a lot of light.