Here are a few important tips for taking digital photographs and how to adjust the parameters in different conditions (ISO, flash/no flash, shutter speed, etc).
You just need to understand how the three controls effect your photos. Aperture, shutter speed, and ISO all have a different effect.
Aperture: this is the opening or iris of the lens. It’s probably the trickiest to understand so I’ll get it out of the way first.
- The lower the number, the more open the aperture is, which lets more light in.
- Aperture also controls the “depth of field”, or in other words, how deep the plane of focus is. Once you focus on something, a portion in front and behind that subject will be in focus. If you shoot at smaller apertures (i.e. f/8 or f/11), a lot of the foreground and background will be in focus. Large aperture openings (i.e. f/2.8 or f/1.4) have a very shallow depth of field, so your subject is isolated from the background.
Shutter speed: simply put, this is how long your shutter stays open.
- the longer your shutter stays open, the more light will be absorbed by the sensor. Of course, longer exposure times will increase the chance of something moving in your frame, causing motion blur.
- the shorter your shutter stays open, the more you’ll freeze the action, but the less light you’ll be recording.
ISO: this is essentially the “volume knob” for your sensor.
- The higher the ISO, the more sensitive your sensor is. That sensitivity comes at the cost of higher noise.
- Generally, you leave your ISO at the lowest setting possible and only turn it up if a larger aperture or a slower shutter speed isn’t an option.
In general terms:
- Broad daylight is of course very bright, so you’ll be using your lowest ISO along with higher F-numbers and faster shutter speeds to prevent overexposure.
- Night time requires long shutter speeds, higher ISOs, and lower F-numbers to record enough light. If you use a tripod and your subject isn’t moving, then you can keep your ISO down and compensate with a longer exposure time.
- Sports generally want faster shutter speeds to freeze the motion. In that case you’ll want lower F-numbers and possibly higher ISO speeds to compensate.