Imaging Terminology Archives - Page 4 of 7

NTSC

What Is NTSC and How Does It Relate to Photography and Video? NTSC is an analogue video standard widely used in the Americas and Japan before the coming of the digital television era. Named after the ‘National Television System Committee’ NTSC dates back to 1941 when the first black and white NTSC system was implemented, NTSC color followed in 1953. The NTSC standard features a refresh rate of 30 frames per second, with each frame being composed of two fields consisting of 262.5 scan lines. NTSC was extremely popular until the late 1990’s when it began to be superseded by …

Opacity

What Does Opacity Mean When Talking About Photography? Opacity is the measure of an objects impenetrability to electromagnetic radiation. When talking about photography the term is used to describes exactly how much an object blocks light from passing through it. An object that completely blocks light is called opaque, no light is able to pass through it. The opposite of opaque is transparent. Many opaque objects will reflect light which can be problematic when taking photos. Knowing the opacity of objects is also very important when designing lenses; lens elements despite very low opacity values will still block small amounts …

Optical Resolution

What Does Optical Resolution Mean When Talking About Photography and Cameras? When talking about cameras and photography the term ‘optical resolution’ describes the total resolution that a digital camera, or optical device such as a scanner is able to capture. The optical resolution is expressed in megapixels or MP, with each megapixel being a total of one million pixels. A camera with an optical resolution of 24.2MP therefore is able to record an image which contains a total of 24200000 pixels. Shot in an image ratio of 3:2 a 24.2MP image would have a resolution of 6016 x 4016 and …

Optical Storage

What Is Optical Storage and how Is it Used in Photography? Optical storage is a storage medium where information is stored on a material that is able to be read optically. Information is stored by marking the optically readable material, and can then be read by shining a laser onto the previously recorded areas. Measurement of whether the light is reflected of absorbed allows a digital readout to be produced which can then be converted back into the original data. Examples of optical storage are CDs and DVDs which you might use to store digital images. Optical storage formats are traditionally …

Optical Zoom

What does Optical Zoom mean when talking about photography? When talking about photography the term ‘optical zoom’ refers to a specific type of lens which allows a photographer to alter the magnification ratio by changing the distance between groups of optical elements within the lens. The zoom ratio of an optical zoom lens is often controlled by rotating the front portion of the lens, this manipulates a mechanism within the lens which moves elements within the lens barrel. On smaller cameras the zoom ratio may be controlled electronically using a motor. Importantly, the focus settings of a lens are not …

Overexposure

What Does Overexposure Mean When Talking About Photography? When talking about photography the term ‘overexposure’ describes what happens when a photographic medium is exposed to incoming light for too long. The resulting image will be ‘overexposed’ and appear extremely bright with highlights appearing ‘blown’ and detail often being completely lost amongst patches of pure white. Overexposure is problematic in situations where a scene contains detail in both light and dark areas; Exposing the image to capture detail in shadows will often result in overexposed light areas, often exposing for both light and dark is impossible without using some form of …

Palette

What Does Palette Mean When Talking About Photography and Image Editing? Also referred to as ‘color palette’ the term ‘palette’ describes the entire range of colors that can be rendered by a digital device such as a camera LCD or a computer monitor. A computer monitor may have a color palette of 16 million colors, an image on the other hand often contains a much smaller number, typically 256. The term is also used to describe a collection of colors, usually displayed graphically in RGB triplets, which a user can select when editing images and re-touching photos. A palette, or …

Parfocal

What Does Parfocal Mean When Talking About Camera Lenses? When talking about photography and photographic lenses a ‘parfocal’ lens is a zoom lens that maintains focus when the focal length of the lens is altered. The opposite of a parfocal lens is a ‘varifocal’ lens. Parfocal lenses are extremely convenient because they allow a photographer to quickly alter their perspective of a scene without having to refocus. The advent of autofocus lenses and digital cameras has somewhat overcome the problems caused by using varifocal lenses as camera software is able to quickly and automatically refocus an image when lens focal …

Perspective

What Does Perspective Mean When Talking About Photography? When talking about taking photographs the term ‘perspective’ describes the positional relationship between the photographer and the subject or scene being captured. The angle at which the photographer views the scene is called their perspective. If you were to stand on the roof of a building and shoot a subject below you you would be shooting from a high perspective, if you were lying on the ground shooting a subject above you you would be shooting from a low perspective. Choosing the best perspective when setting up a scene is a key element …

Photo

What Is the Meaning of the Word Photo and How Is It Used When Talking About Photography? The word ‘photo’ comes from the Greek word for light, and when talking about photography it is used to describe a single image. When you take a picture using a camera you are capturing a photo. A photo may also be referred to as a ‘photograph’, this is a combination of the Greek words for light and drawing; A photograph is a drawing made of light. Someone who takes photos using a camera is a ‘photographer’ or someone who draws with light. The …