Before going to the real world of photography, there are several common terms used by professionals that you should know and understand. It is good to understand these terms so that you will feel comfortable in using the camera and when participating in deliberations with other photographers. So here are list of them:
Aperture – The size of the opening inside a lens that permits light to travel to the camera’s sensor. The size of the aperture is measured in an “f-stop” number. For example – f/8. The smaller the f-stop number, the large the opening inside the lens allowing more light to hit the sensor. The larger the f-stop number, the smaller the opening inside the lens allowing less light to hit the sensor. Aperture numbers include: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32
Aperture Priority (AV) Mode: – A mode that can be selected on a camera that puts priority on the aperture setting. In this mode, an f-stop is chosen by the photographer and the camera automatically adjusts the shutter speed and ISO to achieve proper exposure.
Clipping – Occurs in an image where the intensity in a certain area falls outside the minimum and maximum intensity which can be represented. Clipping can occur in the highlights or the shadows of aphoto. An example is an overexposed image of a sky where the clouds are clipped (or blown-out) resulting in loss of detail.
Exposure – The amount of light that is allowed to fall on to a camera’s sensor during the process of taking a photograph.
Exposure Compensation [EV +/-] – A dial or button on some cameras that allows you to override the automatic exposure output by +/-2 stops.
JPEG: – The term used to describe a type of digital compression used for digital images. This particular compression ratio reduces file size by lowering picture quality.
Depth-of-field – The distance within a photo that is in focus. A large depth-of-field has a deep focus within a scene. An example would be a landscape photo that includes blades of grass closest to the camera that are in focus at the same time as a mountain range further away from the camera. Large depth-of-field requires a higher f/stop number, ex. f/22. A shallow depth-of-field has less of the scene in focus. An example would be a portrait photo where the person is in focus while the background is out offocus. A shallow depth-of-field requires a lower f/stop number, ex. f/1.4.
F-stop – Also known as “aperture”.
Fisheye Lens: – A lens with a wider than normal angle of view that produces an image that is foreshortened in the center and increasingly distorted in the periphery
Focal Length – The distance from the surface of a lens or mirror to its focal point. Also known as focal distance.
Focus: – The area of an image that is sharp and clear. Focus is controlled by automatically by the internal mechanism of a camera or manually by a focus ring.
Histogram – A feature that can be turned on for some cameras that shows a graphical representation of the tonal range (lightness and darkness) within a photo. This is useful to determine if an image is over exposed, underexposed or if clipping is occurring.
ISO – Measures the sensitivity of the camera’s sensor. The lower the number the less sensitive your camera is to light, which results in finer image grain. Higher numbers used in darker situations to get faster shutter speeds. The tradeoff however is more noticeable grain in the shot.
Manual Mode – A mode that can be selected on a camera that gives you independent control over the aperture, shutter speed and ISO. Priority is not given to a specific setting. Proper exposure is determined by the photographer.
Megapixels – A measurement of digital photo quality. A one-megapixel image is made up of one million pixels.
Memory – The electronic storage space for the purpose of storing pictures. Most cameras store memory on an SD card that is inserted into the camera.
Overexposure – Exposing an image so that it looks washed-out or white-looking. This occurs when too much light is exposed on the image