As promised, back to the camera. We’ve talked about what to do with your pictures after you create them; we’ve looked at some of the buttons, knobs and dials on your camera; and we took a look at stopping the action by using the “Sport” mode.
Now it’s time to explore some photography term’s that are important to all the rest of the discussions to come. These are the foundation of moving from taking a snapshot to creating an image that reflects your vision.
Vocabulary; each profession, each sport, each hobby, and so on, has words that are particular to them. Some cross boundaries and become part of the common language, like “strike out” started with baseball, and is in common use now; for example, in dating, or job hunting, and so on. Photographers have a few of our own words that are commonly used when talking about photography. These words help us express ideas and concepts clearly.
Oh no! Not a vocabulary test! I gave those up in Junior high school.
No test; but it is important to recognize some of these words in the context of their use. The list of important ones is pretty small:
Aperture – That’s how big the opening is that lets the light into your camera. This is measured in F-Stops. It works like the iris in your eye. Its purpose is to control the Depth of Field; the smaller the opening the more of your image will be in focus. This is similar to when you squint your eyes to bring something into better focus; you are actually controlling the iris opening in your eyes.
Shutter- This is how long the exposure will be; it is the length of time that the sensor [used to be film] is being exposed to the image you want to capture. Typical shutter speeds are in the 1/60 to 1/200 of a second. According to Wikipedia the average “blink of an eye” is about 1/200 of a second [200 milliseconds]
ISO – This is a measure of how sensitive the sensor is to light. Typical range is 100 to 400. The higher the number, the better it can “see” in low light, but the trade off is image quality.
DOF – Depth of Field. This is used in reference to what will be in focus and what will not be in focus, based on your camera settings. It is a measure of the distance in front of, and behind your subject, that will be in sharp focus. In close up images, that can be sometimes measured in inches, or less. This is what controls whether or not your background will be out of focus, like when taking a portrait; or the whole image will be in focus, like when taking a landscape. Typical range is f/8 to f/14. The lower the number means that the DOF is smaller.
JPEG – The Joint Photographic Experts Group file format is the most popular for storing digital images from your camera.
Megapixel – A pixel, also called a picture element, is the smallest part of an image that can display full color. Even the smallest image sensors now create images with millions of pixels, known as megapixels. A higher number of megapixels is not necessarily better.
White balance – To the human eye, white is white, whether it's being illuminated by the sun, a cloudy sky, a fluorescent tube or a tungsten light bulb. But to image sensors, that white may have a yellow, blue or green cast. White balance is an automatic or manual adjustment to a digital camera's color readings; so whites appear to be white (and all other colors are also accurate) regardless of the illumination source.
That’s it! Not so bad. Here’s the hard part. All of these need to be in balance to get a good image. That’s why your camera is really a computer. It figures most of this out for you.
So why is this important? This is where we start getting creative. We can adjust one of those settings to stop a humming bird in flight, adjust another and we can take pictures of the stars. The trick is knowing which one to adjust and why.