In photography, a beginner often finds himself inundated by terms — and this gets even worse in the SLR world. I have compiled a glossary of terms that I hope will enhance your experience and make understanding photography a little easier for you. As I continue encountering more of these terms, I will update the glossary accordingly.
aberration: generally a lens flaw that contributes to its inability to create a sharp photo that is in-focus. There are many different types of aberrations, such as spherical aberration (where light from different parts of the lens/mirror are brought to different foci) or chromatic aberration (color shifts)
aperture: The size of the opening of the lens. This setting regulates the photograph’s degree of exposure to light. Aperture is often measured in “f-stops”, where the smaller the number, the wider the aperture and the more light coming into the camera. A photo shot “wide open” allows the most light. Aperture is often measured in units of f/1.4, f2, f2.8, f4, f5.6, f8, f11, f16, f22, and f32.
bokeh: In Japanese, this term literally means “blur,” and in photography, this is an out-of-focus quality that comes as a result of certain photographic compositions. Normally, this is seen in photographs that utilize a large aperture.
CCD: Acronym for Couple Charged Device. This is a light sensitive chip in a digital camera. When a picture is taken, the CCD is struck by a light representation of what is seen through the lens. This light is converted to electrons and then becomes translated to a digital value.
CMOS: Acronym for Complementary Metal Oxide Semiconductor. The CMOS is another imaging sensor located in digital cameras. The CMOS is sometimes preferred over the CCD because it consumes less power.
depth-of-field: the focus range of a digital camera. Depth-of-field measures the distance behind and object to the distance in front of the object with all objects appearing in focus. The depth of field can be manipulated by the aperture, where a lens with a smaller opening (highest aperture number) will render the background of a subject the sharpest, while lenses with a large opening (and thus a small aperture number) will render the background of a subject with a lot more blur.
f-stop: Measures the sizes of a camera’s aperture. The higher the f-stop, the smaller the aperture. Thus, a camera lens set at f22 (or f/22) has a smaller lens opening, while a camera lens set at f/1.4 has a very wide lens opening.
full-frame: a method of viewing the entire image without cropping. Most DSLRs today do not offer full-frame viewing capabilities through the viewfinder; instead, the viewing area is approximately 95%.
image noise: See noise.
ISO: A measurement of the light sensitivity of a camera’s imaging sensor. Cameras with a high-ISO setting (e.g. 800, 1600, 3200) can take better pictures at low-light than at lower ISO speeds. However, high-ISO shots generally suffer from image noise.
macro: close-up, often a term applying to the field of photography that enables photographers to capture tiny objects in larger-than-life sizes. This can generally be achieved by purchasing a macro lens.
megapixel (MP): One million pixels. Cameras that have a large number of megapixels are high resolution images and have enhanced quality. This is particularly useful when printing out photos. A rough realistic guide for printouts: 1MP (5×7 inches maximum without loss of quality), 2MP (8×10″), 3MP (11×14″). Large printouts are generally not a concern with modern-day cameras.
monopod: a one legged camera supporting device that functions similar to a tripod. While more difficult to use than a tripod, it is more portable. Often called a Unipod.
noise: The appearance of unwanted grain in a photo. The result often appears off-color from the rest of the image and can be very obvious. Photos shot at a high ISO often appear noisy or “grainy.” Many programs, including Noise Ninja and Neat Image, are equipped to smoothen noisy images using special algorithms.RAW:
prime lens: a prime lens, contrary to a zoom lens, has a fixed focal length. These lenses are not as versatile but are often chosen because of their superior quality.
RAW: a designation for data as it comes directly off the CCD without any in-camera processing. As a result, they are large and uncompressed. This is an ideal solution for those who plan to edit their photographs out of camera using special software. However, some software applications cannot read RAW data.
tripod: a three-legged stand used for supporting the camera and/or lenses. It is especially useful for photos where slow shutter speeds are needed, or for telephoto shots are being taken.