Photographic terms.By Keir McGinn

• Aperture - In photography, an aperture is an adjustable opening in the lens that regulates how much light passes through. Aperture controls depth of field - how much of the image, from foreground to background, appears sharp.

• Bridge camera – This camera type falls between simple point-and-shoots and DSLRs or mirrorless cameras in both size and capabilities. They generally incorporate some advanced features — such as larger sensors, more powerful processors or sophisticated controls — but their lenses are not removable. Some bridge cameras have very long zoom lenses; 30X or greater is not uncommon.

• CMOS – Short for complementary metal oxide semiconductor, CMOS is now the most popular type of image sensor and can be found in everything from cellphones to pro DSLRs. Its low-light sensitivity and ability to provide live preview and video capture to DSLRs have made it extremely popular.

• Focal length – An optical measurement that determines how much of what you see in front of you is captured by your camera's lens.

• ISO – During the film era, ISO (and its predecessor, ASA) were indicators of the film's sensitivity to light. Today, ISO refers to the sensitivity of a camera's image sensor.

• Shutter – Traditionally, this is a mechanical curtain that opens and closes to expose the image sensor. Many digital cameras have an "electronic shutter." The camera collects data from the sensor for a specified amount of time, corresponding to how long a mechanical shutter would expose the sensor.