Time to learn the jaron, hope you find my notes useful.
- Aperture
- Controllers the diameter of the diaphragm, just like the pupil in your eye.
- The aperture setting is adjusted with a series of stops know as f stops.
- Each adjustment to the aperture is called an f stop, each one either halves or doubles the amount of light that enters the camera.
- f/2 is a large aperture.
- f/8 is a medium aperture.
- f/22 is a small aperture.
- e.g. f/2.8 is for dim conditions, where as f/16 is for brightly lit conditions.
- The range is f/1.8 to f/32.
- TOPTIP: Each change of the f number on your camera results in doubling or halving the amount of light entering the lens and hitting the image sensor.
- Depth of field
- Simply put depth of field refers to the distance between the nearest and farthest parts of a scene that appear shart at one focus setting.
- E.g. a lens set at f/2.8 focused on a subject 3 meters away may record sharply everything 3 - 3.5 meters away. Change the aperture to f/16 and it extends to 3 - 5.5 meters and thus bringing more into focus.
- Exposure and metering
- Exposure is how much light the image sensor is exposed to.
- To ensure the image gets the right amount of light, there is a light meter on the camera.
- You can also get a hand-held meter but a built in meter is just fine.
- There are two types of metering, multi zone, which takes in readings from all over the scene and spot metering where a single spot is measured.
- For everyday shooting the multi-zone meter mode is recommended.
- Exposure and ISO
- ISO refers to the speed of film in older analogue cameras and how sensitive that film was to light.
- A ISO film is less sensitive to light, so is perfect for shooting in bright conditions.
- Where as ISO 400 is more sensitive to light so is good for shooting is less than perfect lighting conditions, so in the evening.
- ISO now refers to how sensitive the image sensor is to light.
- Focal length
- Focal length is the distance form the optical center of the lens to the image sensor inside the camera.
- Shutter speed
- Shutter speed sets the amount of time the image sensor is exposed to light.
- Expressed as fractions of a second.
- E.g. 1/30th of a second or 1/125th of a second.
- When shooting at night you need to use a longer shutter time to allow enough light to hit the image sensor.
- Where as in bright conditions you would want a very quick shutter speed, such as 1/1,000th of a second to avoid too much light bleaching out any detail in the exposure.
- Shooting handheld with a shutter speed less than 1/80th of a second can result in camera shake. Use a tripod or flash to overcome this.
- When using the flash to overcome camera shake, a flash will fire for an extremely short amount of time, freezing the position of the subject like a strobe light does. After the flash fires, the shutter remains open and subjects move out. The ambient light keeps coming in, even through the areas where the subjects used to be. The shutter then closes.
- A general rule of thumb is 1/125th of a second for handheld shots and 1/60th should be used when using the flash.