learning the basics of photography
For those of you who have your own DSLR, here is an introduction to help you understand the basic functions of your camera. Photography is ALL about capturing the light. When captured correctly, it yields a properly exposed picture. A proper exposure comes from choosing the correct ‘amounts’ for these 3 ‘ingredients’:
- shutter speed
Think of it like a see-saw on the playground. The base is the ‘ISO’, and one seat is the aperture, the other seat is the shutter speed. You select the ISO first – it is your foundation – and then decide whether you want to base the ‘story’ of your photo on the aperture or the shutter speed. Just like the see-saw, when you pick one side (ex. aperture) to go ‘up’ the other side (shutter speed) must ‘go down.’ Now that you have that picture, let me explain each part individually.
ISO – is the sensitivity of your sensor (what captures the image) of how fast it absorbs the light. Think of it like those paper towel commercials. The thick, better paper towels (low ISO) soak up the water slowly and throughly with no residue. The thin paper towels (high ISO) soak up water fast, but leave behind a water residue. Low ISO (200 or lower) is used in bright sun (since there is plenty of light, the sensor can ‘soak up’ the image slower and can produce richer colors), Mid ISO (400 or 800) is used indoors with flash, and High ISO (1600+) would be used in a low light situation when you can’t use flash – like a church or museum – because it will ‘soak up’ the dim light quicker. Keeping your ISO as low as possible is ideal, because as you go higher along the ISO scale you enter in more ‘noise’ or grain (like the ‘water residue’ from the thinner paper towel) into your photo, and colors become less luminous.
Aperture – is just like the the ‘pupil’ of your eye. When you are in a dark room, your pupils get larger to try and let in more light so you can see. When you are in bright sun, your pupils constrict to cut down on the amount of light entering your eyes, which is why you squint. Aperture, also know as the f-stop, is controlled within your lens. When your aperture is wide open (ex. f-stop of 2.8) you are letting in a lot of light, when you close the aperture down (ex. f-stop 22) you are reducing the amount of light coming through your lens.
Aperture also can be used for creative effect because it alters your depth of field, or how much of your photo is in focus. With a low aperture (ex. f-stop 2.8 – 5.6), you can focus in on a person so that they will be sharp, but the background will be slightly blurred (called bokeh). This calls attention to your subject, and seems to separate them from their surroundings. With a high aperture (ex. f-stop 16+) everything is in sharp focus, even though you are ‘letting in’ less light. Just like when you are driving and can’t see the street sign, you squint & can see everything clearer. This is best for landscape and architectural photography, or when photographing a large group of people.
Shutter speed – how fast the ‘curtain’ in front of your sensor (what captures the image) opens & closes. The longer the shutter stays open, the more light it ‘lets in.’ So if you have a low (wide) aperture of f/4, you will be letting in a lot of light through the lens, so as a result the shutter can open & close faster to let in less light in through the shutter, so that they balance one another.
Shutter speed can be used for creative effect also. The faster the shutter speed (1/1000th of a second), the more you can ‘stop’ motion and your subject appears frozen in time – think of a race car flipping in mid-air. The slower the shutter speed (5 seconds) the more blur you will see – think of watching a waterfall to ‘see’ the rushing water.