This post is for those of you want to start using the more advanced functions of their camera and begin to really unleash your creative side with your photography. Those of you who are more advanced can skip this post altogether and read something else.
Who is this post for?
1. People with a new camera (especially a new DSLR) who want to learn how the camera works and how to use it better.
2. People who are ready to break out of ‘P’ mode on their camera and take more creative control over it
3. People who love to learn and want to make better photographs.
One of the most important things to master when you are learning photography is getting a correct exposure – making sure the photo is not overexposed (too bright) or underexposed (too dark). There will be times you want to over or underexpose, but you want to do it intentionally rather than by accident! Three things affect your exposure: aperture, shutter speed, and ISO. Each one has a different impact on your photos, in addition to making it darker or lighter. Each one has the ability for creative expression, as well as for lightening or darkening the photo. When you are in P mode, the camera is making all the calls on what settings to use. There are two problems with this – how does the camera know what you wanted to do? And even if it does, often it will put you into a slow shutter speed (meaning you now need a tripod) or try to pop up the built in flash, neither of which are good things.
Aperture is the size of the hole that lets light in through the lens. The larger the opening, the more light that can come in and the brighter your image will be. The larger the opening, the smaller the f number will be.
Aperture affects the depth of field of an image; that is to say how much of the image is in focus from front to back. You know how some photos have that wonderful background that is out of focus and draws your attention right into the subject? That’s shallow depth of field, usually used in people photos. (f1.4, f2.8, f4) Sometimes you want everything in focus from front to back, like in a landscape. Use a higher aperture number for more depth of field (f8, f11). Most lenses are sharpest at one to two stops above their lowest aperture number (largest opening). For a 2.8 lens, that would be 4.0 or 5.6 or above. I shoot most of my landscapes at f8 or f11, unless it’s really bright or dark then I’ll go above or below that.
Aperture priority mode is for when you want to control the depth of field for creative purposes, but don’t care what the shutter speed is. Or you want to select the largest aperture opening and get the fastest shutter speed the camera can support. You pick the aperture and the camera picks the shutter speed. Lots of folks shoot in this mode 90% of the time.
Shutter speed is how long the film or sensor is exposed to light through the lens. It’s measured in seconds or fractions of a second, like 1/250th or 1/1000th. Shutter speed affects motion blur in the image. A slow shutter speed (like 1/30th of a second or below) would usually cause a moving subject to appear blurred. This may not be what you want, but it can make for some truly amazing photographs if you get creative and are patient about it.
If you are shooting sports, kids, or anything moving fast and want to get a sharp exposure, you’ll want to shoot at a relatively fast shutter speed, at least 1/250th but preferably 1/500th or 1/1000th. Shooting landscapes or indoors with a tripod, let the shutter speed fall where it may. The subject is not going anywhere, and you can pick your best aperture and select an appropriate corresponding shutter speed.
Shutter priority mode means you select the desired shutter speed and the camera picks it’s own aperture based on the camera’s best guess for an appropriate exposure. This is good for when you care about freezing action but not so much about the depth of field.
ISO (sometimes called ASA by old skool photogs) is the measure of how sensitive the camera sensor is to light. Higher ISO numbers mean the sensor is more sensitive, and given the same aperture and shutter speed, the photo will be brighter. Brighter, and a bit noisier too. However, if there is not much light and you are at your lowest aperture and need a faster shutter speed than you are getting, raising the ISO is a great way to get the photo brighter.
Every camera is different in regard to how much you can raise the ISO to before you get unacceptable noise. Experiment. See what you can live with. You can also buy noise reduction software that will make a nearly unusable photo usable again. The stuff has become amazingly effective.
I love manual mode. I mean really love it. The camera sets nothing for you – you tell it what shutter speed, aperture, and ISO you want to use and you get the same, repeatable exposure over and over again. You can still use the camera’s meter to help you get in the ballpark using the lines on the cheater screen, and that’s a great starting point. You can also go to Aperture mode for a sec and see what shutter and aperture the camera thinks is good, then roll back to manual mode and dial in those settings manually.