It’s the holiday season and everyone seems to be thinking about buying a new camera to capture those great moments that only come around once a year. But for those of you just starting to think about upgrading your camera you may be confused by some of the terminology used: words like CMOS, ISO, and megapixels. How can you make an educated decision without knowing what everything means? It also doesn’t help that there are so many cameras to choose from these days when you walk into an electronics store. Not knowing what the most important features makes it all that more difficult to decide. Here we’ve put together a list of ten digital camera terms that can help you make a better decision. The descriptions may even help you take some better photographs. You’ll find most of these terms refer to both digital SLR and point-and-shoot cameras. For your reference, a digital SLR (Single-Lens Reflex) is a camera with interchangeable lenses. Lenses for digital SLRs are often purchased separately from the camera body. A point-and-shoot is usually a smaller pocket-sized camera with a fixed lens, available in many different shapes and colors.


The CMOS is the heart of a digital camera. CMOS, an acronym for “Complementary Metal Oxide Semiconductor,” is the sensor that captures light to create images. For 150 years, film was the element that stored images that could be revealed later through chemical processing. Now, it is the CMOS that captures an image, and is processed instantly by the camera’s software, or can be stored for processing later. CMOS sensitivity is measured in pixels not film grain, as in 10 Megapixels. CMOS’s are often also described by their physical measurements, for example, 35.9 x 24.0mm.

2. MP (Megapixels)

Megapixels, abbreviated as MP, represents 1,000,000 pixels. When you talk about CMOS Sensors as mentioned above, you describe how many pixels it contains. For example, a high-end digital SLR may have a 20.2MP CMOS Sensor. Be wary of large pixel counts on inexpensive cameras, however. Those pixels are probably software-generated rather than actual pixels on a CMOS.

3. Image Stabilization (IS)

Also known as Anti Shake, Image Stabilization is a technology that reduces the amount of camera shake while taking a picture, therefore improving picture sharpness. Image Stabilization can be achieved both in-camera and in-lens, and uses software along with sensors to limit movement. Image Stabilization helps you hand-hold cameras at slower speeds than you would be capable of without the technology.

4. ISO

The ISO number represents a sensor’s sensitivity to light. The higher the number, the more sensitive a camera will be to light in darker areas. Traditional film cameras do not have an ISO sensitivity, rather, the film that was used in the camera had ISO specifications. ISO is an acronym for International Standards Organization, and comes from the Greek word isos, meaning, equal.

5. Zoom

The term zoom is used to describe how a lens can move forward and closer to a subject without moving the camera. Point-and-shoot cameras will often specify a lenses’ capabilities, as in “14x zoom lens.” However, look for the term “optical zoom.” This is the natural length provided by the glass in the lens. Digital zoom, as it’s often called, doesn’t have as high quality as the zoom is processed by software in the camera. True optical zoom may be represented as “7.1x Optical Zoom.”

6. Aperture

Aperture is the opening at which light passes through a lens to expose on a sensor or piece of film. The aperture changes in an automatic camera according to how much light is needed. A smaller aperture can be used when there is plenty of light, while a larger aperture may be needed for lower light situations. Aperture is measured by F-Stop, which in turn affects “depth of field.” Lenses with smaller F-Stops like f2.0 are generally higher quality lenses because of their sensitivity to light.

7. F-Stop

F-Stops determine the size of the aperture and are indicated as f4, f5.6, f11, f22, etc. Older camera lenses will click into those F-stops, while new digital lenses allow the aperture to open to sizes in-between those designated F-stops as in f8.0, f10, etc. The larger the F-stop number (e.g. f22), the smaller the lens opening. The smaller the F-Stop number (e.g. f4) the larger the opening. F-Stops can also be used to set depth-of-field, or range of focus. Portraits generally don’t have much depth-of-field, as a majority of photographers tend to like selective focus on someone’s face rather than the background. To achieve low depth-of-field you would use a large aperture such as f4. Landscapes and architecture, on the other hand, are generally preferred to be in focus. In this case you would want a larger aperture for more depth-of-field, as in f22.

8. Frames-Per-Second (FPS)

Frames-per-second refers to how many shots you can take within the timespan of one second. Shooting many frames per second is essential for sports and action photographers who will at times select the best photo from hundreds of frames. A mid-range point-and-shoot camera may be able to take 5 frames per second, while a high-end SLR may take over 10 frames-per-second.

9. RAW

Mainly found in digital SLRs (although some point-and-shoot mid-range cameras shoot in RAW such as the Canon PowerShot G16), RAW is unprocessed image information from the camera’s sensor. RAW allows a lot more flexibility in editing an image later, because you can use software to adjust exposure, sharpness, color saturation, and other image qualities before saving the as a jpg, tiff, or other image file format. RAW formats may be labeled differently depending on the brand. For example, Nikon uses the extension NEF for files in the RAW format.

10. Hot Shoe

A hot shoe is the flash mounting bracket found on many digital SLRs and mid-range point-and-shoot cameras. If you want to become an expert in shooting with flash, you should think about getting an external flash unit and mounting it on your camera’s hot shoe. That way, the flash can come from a higher angle upon the subject rather than straight on, which causes a flattening or washing out of the subject. A mounted flash unit can also be angled to bounce light off the ceiling, or, mounted on a tripod away from the camera using a flash cord or wireless sync mount.

Jeff Chabot

Jeff Chabot has a background in web development and design, as well as working in broadcast television as a studio engineer, lighting director and editor. He frequently writes about technology, broadcasting, digital entertainment, and the internet.