A Changing Picture
Total Page:16
File Type:pdf, Size:1020Kb
Glossary of Photographic Terms Expert knowledge means success Contents 1. Introduction 1. Glossary Terms in Alphabetical Order: 1. A 2. B and C 3. D 4. E and F 5. G 6. H and I 7. J, L and M 8. N and O 9. P and R 10. S 11. T, U, V, W, X and Z 11. Further Information Glossary of Photographic Terms Note: This publication has not been updated and are classified as D-type AF Nikkor since it was last published. Some of the lenses. hyperlinks may have changed and may need updating. In addition, some of the information AF or Auto Focus in this publication may be out of date. Most modern SLR lenses have this function now. The lens automatically focuses on the subject as quick as the eye. With an SLR you Introduction can normally select manual focus if The following glossary contains terms necessary. What is a Camera? relating to digital cameras including SLR and AI (Nikon) DSLR cameras as well as photographic The term camera Automatic index; Nikon's system for telling comes from the the camera's exposure meter what the lens' effects. The list may not be complete as new camera obscura maximum aperture is. terms and acronyms are arising all the time. (Latin for "dark AI/S (Nikon) chamber"), an early Automatic index/Shutter; Nikon's lens mount mechanism for permitting automatic operation in shutter- projecting images. Glossary priority and program auto-exposure The modern camera systems. evolved from the camera obscura. A Aliasing This is an effect caused by sampling an AA Filter image at too low a rate. It causes rapid Most Digital SLR's have a "Low Pass Filter" change (high texture) areas of an image to (LPF) or AA (Anti-Aliasing) Filter in front of appear as a slow change in the sample the CCD or CMOS sensor. This helps to image. Once this has happened, it is eliminate colour aliasing problems, or the extremely difficult to reproduce the original "moire" effect. image from the sample. ACR (Adobe Camera Raw) Angle of View This is the program that comes up by default This is calculated by the focal length of the in CS3 when you open a RAW file. It is the lens and the size of the image sensor. The program used to make the initial 35mm equivalents differ according to the adjustments before transferring the RAW file sensor size. to CS3, making further adjustments and then saving as .tiff, .jpg etc. Aperture The lens opening that allows more, or less Adjustable Camera light onto the sensor formed by a diaphragm A camera with manually adjustable settings inside the actual lens. It is measured in for distance, lens openings, and shutter f/stops. speeds. Aperture Priority Adjustable-Focus Lens Often abbreviated as A or Av (for Aperture A lens that has adjustable distance settings. value) on a camera mode dial. It is a setting on some cameras that allows the user to Adjustment Brush choose a specific aperture value while the There are many new features in the camera selects a shutter speed to match. Lightroom 2 photo software but the main The camera will ensure proper exposure. one is the adjustment brush. This powerful This is different from manual mode, where tool enables you to make local adjustments the user must decide both values, shutter to your photos with any combination priority where the user picks a shutter speed exposure, brightness, contrast, saturation, with the camera selecting the aperture to clarity, sharpness, and colour settings. match, or program mode where the camera selects both. AE Automatic Exposure: Three kinds are Aperture Priority AE available - programmed auto exposure, When using this mode, the user selects the aperture-priority auto exposure and shutter- aperture giving control over the Depth of priority auto exposure. Field. A large aperture letting more light in gives a small depth of field, meaning not AE Lock much will be in focus. Whereas a small Used to hold an automatically controlled aperture, not letting much light in, will give a shutter speed and/or lens aperture, in case greater depth of field or more will be in focus you need to recompose your picture but from the front to back of the image. want to retain an previous exposure reading. APO AF-I (Nikon) Apochromatic; a type of lens which focuses Lens with built-in autofocus drive motor. CPU different wavelengths of light on the film is also built in. AF-I Nikkor lenses send plane for improved image sharpness. information on distance to the camera body Especially useful in telephoto lenses. (Chromatic aberration is corrected). 1 Glossary of Photographic Terms AS cloud. Where two shadows overlap, the Antishake - often understood to be the same shadow is called umbral (see also Fog Bow). as Image Stabilization, but may only refer to a camera automatically increasing ISO. Buffer Temporary storage areas held in your ASA camera or computer’s RAM. Its acts as a American Standards Association. (also see temporary holding area for data that will be ISO). manipulated by the processor before saving What is it to another device. For example if you are ASL shooting in continuous mode, when the RAM Photography? Aspherical Lens: allows for high quality, yet buffer on your digital camera is full it will “Photography is compact and lightweight lenses. slow to a much slower rate while the buffer the art, science empties to your compact flash card or other and practice of Aspect Ratio device. creating durable The ratio of horizontal to vertical dimensions images by of an image. For example, 35mm slide film = recording light or 3:2, TV = 4:3, HDTV = 16:9, 4x5 Film = other 5:4. C electromagnetic radiation, either Aspherical Lens CAF electronically by A lens with edges flattened so that it is not a CAF stands for Continuous Auto Focus. What means of an image perfect sphere. These produce a much continuous auto focus does is it takes the sensor or superior image. most prominent object in your shots’ chemically by composition and it uses this as its focal means of a light- Automatic Exposure point. However, the system is not always sensitive material The camera sets the shutter speed and perfect at guessing what you want that such as aperture for the correct exposure according object to be. You can compensate for this by to the light. photographic film. zooming into the object you want to be in Typically, a lens is focus, hold that zoom until the object is used to focus the Average Metering sharp, and then slowly zoom out. light reflected or In this metering mode the camera will use the light information coming from the entire Card Reader emitted from scene and averages for the final exposure Used for transferring data from your flash objects into a real setting, giving no weighting to any particular memory card to your PC. A better way of image on the light- portion of the metered area. transferring your image files than connecting sensitive surface the camera to your PC. Sometimes the inside a camera AWB cameras circuitry can become corrupt. during a timed This stands for Automatic White Balance. exposure. The Most digital cameras have this feature where CCD (Charged Coupled Device) result in an the camera sets the white balance. Override This is a light sensitive chip used in your electronic image is available in most DSLRs. digital camera for image gathering. The CCD sensor is an Pixels gather the colour from the light and electrical charge at B pass it to the shift register for storage. CCD's each pixel, which is are analogue sensors, the digitising occurs electronically when the electrons are passed through the A processed and B & W to D converter. This "Analogue to Digital" stored in a digital Abbreviation for Black and White. converter converts the analogue signal to a image file for digital file or signal. Barrel Distortion subsequent display A common geometric lens distortion causing Centre-Weighted Average Metering or processing.” an acquired image to pucker towards the In this system, the meter concentrates Wikipedia centre and be rounded along the outer between 60 to 80 percent of the sensitivity edges. towards the central part of the viewfinder. The balance is then "feathered" out towards B (Bulb) the edges. Some cameras will allow the user At the B setting, the shutter remains open as to adjust the weight/balance of the central long as the shutter release button remains portion to the peripheral one. One advantage fully depressed. of this method is that it is less influenced by small areas that vary greatly in brightness at Bracketing the edges of the viewfinder: as many Take a series of pictures taken at different subjects are in the central part of the frame, exposures. consistent results can be obtained. Brocken Spectre Channel The Brocken Spectre is basically a shadow One piece of information stored with an (the photographer's shadow) cast on and in image. For example, a true colour image has a cloud (fog). As the cloud is not an object 3 channels, red, green and blue. with a sharp boundary, but more or less transparent to some optical depth, the shadow figure is a three-dimensional image cast not only on the cloud but also in the 2 Glossary of Photographic Terms Chroma The colour of an image element or pixel. A D chroma is made up of saturation plus the hue values but is separate from the Dark Frame luminance value. A noise reduction process where a camera takes a second exposure of a black frame after CIFF the camera takes a long exposure image.