Understand Exposure

Understand Exposure
Exposure, in the photography world, is a very broad term and you'll need to understand it better. Your camera has manual modes like Aperture, Shutter, Program, and Manual. Aperture Mode allows you to control the f-stop on the camera and the camera will adjust everything else. Shutter is similar to Aperture but controls the shutter speed. Program is essentially an auto setting and Manual allows for full manual control over the camera. Most professionals tend to use Manual. Reading your camera's meter also comes into play here.

With shooting in Manual exposure comes learning a couple of key new terms:

Shutter Speed: Your camera has a shutter, and it can stay open for certain amounts of time depending on what the user dials into the camera. It is typically displayed as a fraction or a whole number. For example:

• 1/15 = A fifteenth of a second. This is fairly quick and in photojournalism, you're typically taught to never shoot below this while hand-holding a camera.
• 1/2000= A two-thousandth of a second. This is very quick and perhaps may be used during sports.
• 2"= 2 seconds long. This is a slow shutter speed and will let in quite a bit of light and movement to be captured.
• 20"= 20 seconds. Your cameras shutter will stay open for 20 seconds and therefore allow in large amounts of light and also allow for lots of movement to be captured.

The longer the shutter speed the more motion that will be captured and the steadier the photographer needs to remain. This is great for capturing nighttime scenes. As a note, use a tripod.

The faster the shutter speed the less motion will be captured. This is great for capturing fast moving objects like sports action. On your camera, this can be seen with the S mode.

F-Stop: This is also known as your Aperture. Your aperture not only controls how much of your image is in focus or not, but like your shutter speed it can also control how much light comes into the lens of your camera and hits the sensor (the equivalent of film.) In general:

• f/1.4 = Enables high shutter speeds, not much is in focus. Best used for concerts and dimly lit situations. Wedding photographers love lenses at this speed.
• f/2.8 = Enables almost as high shutter speeds, more is in focus. This is typically the aperture that many photographers love for taking portraits and is the minimum aperture that many photojournalists will demand of their lenses.
• f/11 = Needs slower shutter speeds to let in enough light to create a balanced exposure, much more is in focus.
• f/22 = Needs the slowest of shutter speeds. Everything you point your lens at should be in focus the way that the human eye will see it with 20/20 vision. Shooting at this exposure is best done with a flash unless there is tons of available bright light.

On your camera this is also known as AV mode.

ISO: The ISO (or ASA as it was in the film days) is the current light sensitivity setting of your camera's sensor. The general rule is the higher the ISO, the more sensitive your camera will be to light and the grainier your images will be. The grain is also known and often referred to as image noise. In contrast, the lower the ISO, the less sensitive the camera will be to light and the less grain will appear on your images. Higher ISOs allow for faster shutter speeds. Similarly, larger sensors allow for less grain at higher ISO settings.

• ISO 100 = One of the lowest ISO settings, it is great for daylight use and provides nearly no image grain.
• ISO 400 = a favorite of many photographers even today, it is great for twilight use and if you look very closely there is a bit more grain but in modern digital cameras there is very little.
• ISO 1600 = The limit for many professional photographers even today, this setting is much more suited towards low light or high action where you need to stop fast movement. It is often the choice of event and sports photographers.
• ISO 6400 = This is where some sensors really start the push their physical limits. ISO 6400 provides even better low light sensitivity and can stop fast action, but often delivers very grainy images that require special processing in post-production programs like Photoshop.