PHOTOGRAPHY 2

SLR (Single-Lens-Reflex)

A camera that utilizes a prism and mirror system to project the image seen by the lens onto a focusing screen located below the prism housing. The image the user sees in the viewfinder is identical to the image being recorded. The advantage of SLRs is that you get to view the exact scene the camera will be recording.

Lossy

A data-compression technique that can reduce the detail of a digital image file. Most video compression techniques utilize lossy compression. See non-lossy or lossless.

HDSLR

A digital single lens reflex camera (DSLR) that can also capture high-definition video. Most current DSLRs are also HDSLRs, making the terms almost interchangeable

Shutter

A mechanism in the camera that controls the duration of light transmitted to the film or sensor. Leaf-shutter lenses, which include most view camera lenses and many medium-format lenses, contain their own proprietary shutters.

Megapixel

A megapixel contains 1,000,000 pixels and is the unit of measure used to describe the size of the sensor in a digital camera.

Inkjet

A printing method in which the printer sprays micro-jets of ionized ink at a sheet of paper in droplet sizes as small as 2 picoliters. Magnetized plates in the ink's path direct the ink onto the paper in the desired shapes and patterns to make an image.

Noise Reduction

A process in a digital camera's image processor in which the artifacts caused by "pushed" ISO ratings or other electrical or heat-related artifacts are suppressed or eliminated in an image.

Time Lapse

A series of photographs captured over a period of time. These images can be captured in variable or set time intervals over the course of seconds, minutes, hours, days, weeks, etc.

Non-lossy (aka lossless)

A term that refers to data compression techniques that do not remove image data details, to achieve compression. This method is generally less effective than lossy methods in terms of reducing file size, since the entire original image is retained. See lossy.

F-Stop (Aperture)

A term used to describe the aperture, or diaphragm opening of a lens. F-stops are defined numerically: f/1.4, f/5.6, f/22, etc. Larger, or wider apertures, allow more light to enter the lens, which calls for faster shutter speeds. "Faster" (wider) apertures also allow for selective focus (narrow depth of field), while slower (smaller) apertures allow for greater depth of field. Wider apertures are preferable for portraits, while smaller apertures are preferable for landscapes.

Lag Time

Also known as shutter lag, lag time refers to the delay that sometimes occurs between the time the shutter button is pressed and the time the shutter fires. Shutter lag is most prevalent when using less expensive point-and-shoot cameras.

PNG (Portable Network Graphics)

Developed as a patent-free alternative to GIF, this format is used for lossless compression for purposes of displaying images on the World Wide Web. Adopted by the WWW consortium as a replacement for GIF, some older versions of Web browsers may not support PNG images.

Exposure

Exposure is the phenomenon of light striking the surface of film or a digital imaging sensor. The exposure is determined by the volume of light passing through the lens aperture (f/stop) combined with the duration of the exposure (shutter speed).

SD Card (Secure Digital)

Far smaller than CompactFlash (CF) cards, Secure Digital memory cards have enabled camera manufacturers to further reduce the size of digital cameras. They are also commonly found in cell phones, PDAs and other small electronic devices that incorporate removable memory. Newer-generation (and faster) SD cards include SDHC and SDXC memory cards.

Fringing

Fringing, commonly associated with less expensive lenses, describes the "bleeding" of color along the edges of high-contrast portions of a digital image. Fringing often shows up as cyan blurring on one side of a high-contrast object, complemented by red or magenta blurring on the opposite side of the object.

GIF

Graphic Interface designed by CompuServe for using images online. This is a 256-color or 8-bit image.

Rig

In HDSLR terms, this is a support and focus system designed especially for capturing video footage with an HDSLR camera. Since the ergonomics of the DSLR camera were not meant for the process of video capture, an HDSLR rig provides the support, focusing, and monitoring capabilities that are more inherent in single-purpose video cameras.

Memory Card

In digital photography, a memory card is a removable device used in digital cameras to store the image data captured by the camera. There are several different types of memory cards available including CompactFlash, SmartMedia, SD/SDHC/SDXC, XD, and others.

LCD (Liquid Crystal Display)

LCD screens, usually found on the rear of digital cameras, allow you to preview and review photographs you are about to take or have taken. LCDs utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light and producing an image in color or monochrome.

Raw Files

Many pro and semi-pro digital cameras include the option for capturing raw files, which—unlike JPEGs, TIFFs, and other file formats—contain all of the data captured during the exposure in an unedited format. When processed, raw files can be adjusted far more extensively than images captured in other imaging formats, and can be saved as JPEGs, TIFFs, etc. The original raw file remains unaltered and can be reprocessed at any time for other purposes.

Micro Lenses

Micro lenses are commonly mounted on the tops of the light-gathering portion of pixels (aka photons) and are often angled along the edges of camera sensors to capture and redirect light back into the pixel, as a method of reducing light falloff on the edges of the image and redirecting it for image processing. Not to be confused with NIKKOR micro lenses.

Red-Eye

Red-eye is the term used to describe the reddened pupils of a subject's eyes that sometimes occurs when photographing people or pets with an electronic flash. This effect often occurs when the pupil of the eye is dilated, usually in a low-light environment. The red color appears as a result of the light from the flash striking the rear portion of the eye and illuminating the blood vessels. Red-eye can often be avoided by placing the flash farther than 6" from the camera lens. The reason red-eye is most common with compact digital cameras is because the flashtube is often adjacent to the lens, thereby causing light to enter a subject's pupil head-on. A common pre-capture cure for red-eye is to bounce the flash onto an adjacent wall or ceiling, which softens the light and eliminates any red-eye effects.

Resolution

Refers to the number of pixels, both horizontally and vertically, used to either capture or display an image. The higher the resolution, the finer the image detail will be.

Saturation

Saturation is the depth of the colors within a photographic image. Photographs with deep levels of color are described as being heavily saturated. A photograph with lighter levels of saturation is described as having a muted color palette. A totally desaturated color photograph becomes monotone—or black and white.

Pixel

Short for picture element, pixels are the tiny components that capture the digital image data recorded by your camera. Pixels are also the individual components that collectively recreate the image captured with your digital camera on a computer monitor. The more pixels there are, the higher the screen or image resolution will be.

Thumbnails

Small, contact sheet-sized image files used to reference or edit digital images. The images that appear on a camera's LCD are thumbnail images of the larger file.

Spot Metering

Spot metering is the measurement of very small portions of the total image area. Older cameras, as well as less-expensive digital cameras, only offer a single, centrally located measuring point, usually between 1 to 5 degrees in coverage. Many newer cameras offer a selection of 3, 5, 7, 11 or more reference points for selective metering, which enable you to selectively measure important areas of the photograph, including areas that are off-center to the frame. Spot metering is a very effective way to take readings of backlit subjects.

Viewfinder

System used for composing and focusing on the subject being photographed. Aside from the more traditional rangefinder and reflex viewfinders, many compact digital cameras utilize LCD screens in place of a conventional viewfinder as a method of reducing the camera's size (and number of parts). In recent years, electronic viewfinders (EVFs) have become increasingly better and are they slowly finding their way into traditional DSLRs.

TIFF (Tagged-Image File Format)

TIFF files are flexible bitmap image files supported by virtually all paint, image editing, and page-layout applications. Also, virtually all desktop scanners can produce TIFF images. This format, which uses the .tif extension, supports CMYK, RGB, Lab, and grayscale files with alpha channels and Bitmap files without alpha channels. TIFF also supports LZW compression, a lossless compression format.

Remote Capture

The ability to trip the camera shutter from a distance using a cable release or wireless transmitter / transceiver.

White Balance

The camera's ability to correct color cast or tint under different lighting conditions including daylight, indoor, fluorescent lighting, and electronic flash. Also known as "WB," many cameras offer an Auto WB mode that is usually—but not always—quite accurate.

Memory

The camera's file-storage medium. Most cameras use flash memory, which is a safe, highly reliable form of storage that doesn't need power to hold the images after they are saved. Flash memory won't erase the images unless the user chooses to do so. Some cameras contain a limited quantity of built-in memory, but certainly not enough to capture more than a dozen or so images.

JPEG (Joint Photographic Experts Group)

The de facto standard for image compression in digital imaging devices. JPEG is a "lossy" compression format, capable of reducing a digital image file to about 5% of its normal size. The resulting decompression of the file can cause "blockiness," "jaggies," or "pixelization" in certain digital images. The greater the compression levels, the more of a chance pixelization or "blockiness" will occur. The greater the pixel count, the less of a chance pixelization will occur.

export

The process of sending a file out through a specialized mini-application or plug-in, so as to print or compress it. This term is also used to describe the action of saving the data to a specialized file format, i.e. JPEG or GIF.

Underexposure

The result of recording too little light when taking a picture, which results in a dark image. In digital imaging, underexposure can be corrected to a certain extent by the use of image-editing software, depending upon how underexposed your image is. Raw files offer more latitude than JPEGs and TIFFs for correcting underexposure.

Over Exposure

The result of recording too much light when taking a picture, which results in a lighter image. In digital imaging, overexposure can usually be corrected to a certain extent by the use of image-editing software, depending on the degree to which an image is overexposed. Raw files offer more latitude than JPEGs and TIFFs for correcting overexposure.

File Format

The way an image is saved to a digital camera's memory. JPEG, TIFF, and raw (DNG or other proprietary file formats) are the most common file formats found in digital cameras.

Watermark

Traditionally, a watermark is an image or icon that is embedded into paper for security purposes (American paper currency has a watermark). In digital photography, a watermark refers to information that is embedded in the image data to protect the copyrights of the image.

Megabyte

1,024 Kilobytes, written MB, is used to refer to the size of files or media, such as hard drives. The number refers to the amount of information or image data in a file or how much information can be contained on a memory card, CD or DVD, hard drive or disk.