In addition to the assignment below, I also handed out my suggestions for getting started and some info on exposure. Here it is:
My recommendations for STARTING OUT:
1. READ YOUR MANUAL. Every camera is different and you need to know yours. Besides that, most manuals give really great ideas about which settings to use for which pictures. Keep it in your bag and refer to it often.
2. GET A BOOK. I got Digital SLR Cameras & Photography and just read a little every day, taking notes as I went. It was mostly what I'd heard before, but rereading always helps really understanding. Just read a little every day and get other books on children's photography, or anything else you're interested in.
3. PRACTICE EVERY DAY. Just going outside or chasing your children around at least for 5 minutes a day really, really helps. Reading can only go so far. If you don't get it, keep going. It will click. Practice different kinds of things—motion, lighting, landscapes, closeups, everything.
4. PLAY AROUND WITH PROCESSING. Every single digital photographer processes their photographs afterward. Choose your favorite program (photoshop, picnik, etc.) and play around with your pictures to learn how things work. It really makes a difference in your pictures.
Exposure: how light works with your camera.
When you venture out of your camera's automatic settings, you need to be able to understand the three ways light enters and interacts with your camera. This exposure triangle is made up of ISO, shutter speed, and aperture. When you adjust one, you need to adjust the others in order to get the perfect exposure.
ISO:
In traditional (film) photography ISO (or ASA) was the indication of how sensitive a film was to light. It was measured in numbers (you’ve probably seen them on films – 100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you’re taking.
In Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography – the lower the number the less sensitive your camera is to light and the finer the grain. Higher ISO settings are generally used in darker situations to get faster shutter speeds (for example an indoor sports event when you want to freeze the action in lower light) – however the cost is noisier shots.
SHUTTER SPEED:
Defined most basically – shutter speed is ‘the amount of time that the shutter is open’.
In film photography it was the length of time that the film was exposed to the scene you’re photographing and similarly in digital photography shutter speed is the length of time that your image sensor ’sees’ the scene you’re attempting to capture.
Let me attempt to break down the topic of “Shutter Speed” into some bite sized pieces that should help digital camera owners trying to get their head around shutter speed:
Shutter speed is measured in seconds – or in most cases fractions of seconds. The bigger the denominator the faster the speed (ie 1/1000 is much faster than 1/30).
In most cases you’ll probably be using shutter speeds of 1/60th of a second or faster. This is because anything slower than this is very difficult to use without getting camera shake. Camera shake is when your camera is moving while the shutter is open and results in blur in your photos.
If you’re using a slow shutter speed (anything slower than 1/60) you will need to either use a tripod or some some type of image stabilization (more and more cameras are coming with this built in).
APERTURE:
Put most simply – Aperture is ‘the size of the opening in the lens when a picture is taken.’
When you hit the shutter release button of your camera a hole opens up that allows your cameras image sensor to catch a glimpse of the scene you’re wanting to capture. The aperture that you set impacts the size of that hole. The larger the hole the more light that gets in – the smaller the hole the less light.
Aperture is measured in ‘f-stops’. You’ll often see them referred to here at Digital Photography School as f/number – for example f/2.8, f/4, f/5.6,f/8,f/22 etc. Moving from one f-stop to the next doubles or halves the size of the amount of opening in your lens (and the amount of light getting through). Keep in mind that a change in shutter speed from one stop to the next doubles or halves the amount of light that gets in also – this means if you increase one and decrease the other you let the same amount of light in – very handy to keep in mind).
One thing that causes a lot of new photographers confusion is that large apertures (where lots of light gets through) are given f/stop smaller numbers and smaller apertures (where less light gets through) have larger f-stop numbers. So f/2.8 is in fact a much larger aperture than f/22. It seems the wrong way around when you first hear it but you’ll get the hang of it.
Depth of Field and Aperture
There are a number of results of changing the aperture of your shots that you’ll want to keep in mind as you consider your setting but the most noticeable one will be the depth of field that your shot will have.
Depth of Field (DOF) is that amount of your shot that will be in focus. Large depth of field means that most of your image will be in focus whether it’s close to your camera or far away.
Small (or shallow) depth of field means that only part of the image will be in focus and the rest will be fuzzy.
BRINGING IT TOGETHER
Remember that thinking about any of the exposure triangle elements in isolation from the other two elements is not really a good idea. As you change one you’ll need to change one or both of the other elements to compensate for it.
For example if you speed up your shutter speed one stop (for example from 1/125th to 1/250th) you’re effectively letting half as much light into your camera. To compensate for this you’ll probably need to increase your aperture one stop (for example from f16 to f11). The other alternative would be to choose a faster ISO rating (you might want to move from ISO 100 to ISO 400 for example).
The best thing to do is practice playing around with all three on manual setting until you understand how they work. Even zooming in will sometimes change the aperture, so be careful. Semi-automatic settings are also helpful in that you can change shutter speed and the aperture will change automatically, or vice versa. Keep trying until you figure it all out.