Photo Shoot: Aerial Photography Terms
Here are some of the terms used in aerial photography, to help you understand the process. We are always happy to answer client questions and discuss your specific requirements. See also our FAQ page.
Call Warren White at 805-709-8455 to discuss your project, or email info@aerialperspectives.com
AGL – An aviation term used to described the altitude above the ground level rather than above mean sea level.
Altitude - In aviation, the term altitude can have several meanings. It is a fundamental tenet of flight safety that both parties exchanging information concerning this topic are absolutely clear which definition is being used.
- True altitude is the elevation above mean sea level. (MSL)
- Height is the elevation above a ground reference point, commonly the terrain elevation. (AGL)
Analog photography – photography made by a progressive changing image medium; usually one based on chemical process (photographic film). This was the dominant form of photography for much of its history, but is now being supplemented by digital photography.
Camera Shake – an unintentional movement of the camera during exposure, thereby causing un-sharpness in the image.
Cloud Shadows – Cloud shadows are dark areas in an aerial photograph where the sun is blocked by clouds.
Construction Progress - Construction Progress photography consists of aerial photographs taken of a project at different intervals in the construction phase.
Contact Sheet – A contact sheet is an 81/2 x 11 sheet of photo paper with 6 to 8 color images, generally referred to as proofs.
Coordinates – Latitude and longitude coordinates of a site, when interred into a GPS, will allow the pilot to fly directly to the site
Depth of Field – The distance through which the subject may extend and still form an acceptably sharp image, in front of and beyond the plane of the critical focus.
Digital Photography - Digital photography, as opposed to film photography, uses CCD array to record and capture the image as binary data. As such, the images can be displayed, printed, stored, manipulated, transmitted and archived using various kinds of digital technology, including personal computers and the Internet.
DPI - (Dots per inch) refers to the physical (hard copy) depiction, such as what results from a printer. (You can touch the dots on a printed image). Printer resolution refers to how the ink is put down on the paper. The greater the DPI a printer can produce, the finer the detail will be in an image on paper.
Focal Length – The distance between the center of a lens (the principal point) and its focal point.
Focal Plane – The plane at which a lens forms a sharp image.
Focal Point – The point of either side of a lens where light rays entering parallel to the axis coverage.
Focus – The point at which light rays are converged by a lens.
GPS – Global Positioning Systems are designed for detailed electronic charting and simple operations of powerful navigation devices used to help pilots fly anywhere in the world.
Gyro-Stabilized Lens – An electrically powered camera lens that incorporates a gyroscope to cushion the lens from vibrations, therefore, producing a crisper image.
High Camera Angle – The High Angle shows more roofs and is generally used for planning purposes. The High Angle is shot more straight down and shows much less of the surrounding property, yet shows the boundaries better.
High Area Oblique – Shows more of the surrounding area and generally includes the horizon.
JPEG - Short for Joint Photographic Experts Group, and pronounced jay-peg. JPEG is a file extension that is a lossy compression technique for color images. Although it can reduce files sizes to about 5% of their normal size, some detail is lost in the compression.
Low Camera Angle – The Low Camera Angle shows less of the roof and is generally more of an architectural rendering.
Low Area Oblique – Shows less of the surrounding area and generally does not show the horizon.
Medium Camera Angle – The Medium Camera Angle is shot from approximately 1000 AGL and is about 45 DEGS. This is the recommended camera angle.
Normal Lens – Lens with a focal length equal to the diagonal of the film format. It produces an image that appears to have normal perspective and angle of view.
Pixel – The smallest unit of area of a digitized image, normally a square. The number of pixels in which the image is recorded determines its resolution.
PPI - (Pixels per inch) exclusively refers to the computer’s digital image representation. PPI is a term used to describe the resolution of an image on a computer screen. PPI always refers to digital representation, that is, how the pixels are arranged in a digital photo, and it is something you cannot touch. (You cannot pick up a pixel with your fingers or place a pile of pixels on a table. Pixels only reside in a file and on a computer screen.)
RAW - A raw image file (sometimes written RAW image file) contains minimally processed data from the image sensor of a digital camera or image scanner. Raw files are so named because they are not yet processed and ready to be used with a bitmap graphics editor or printed. Normally, the image will be processed by a raw converter in a wide-gamut internal colorspace where precise adjustments can be made before conversion to an RGB file format such as TIFF or JPEG for storage, printing, or further manipulation.
Resolution – The ability of a lens to distinguish between closely spaced objects, also known as resolving power.
Scale – Usually refers to changing the ratio of an image to fit a print or other boundary.
Stock Aerials – Aerial images that are taken by an aerial photographer and used to sell at a later date. Usually not contracted by someone to take specific images.
Telephoto Lens - A telephoto lens is a specific construction of a long focal length photographic lens that places its optical center outside of its physical construction, such that the entire lens assembly is between the optical centre and the focal plane.
TIFF - Tagged Image File Format is a computer file format used for storing images, including photographs and line art.
Vertical Photography – Aerial photography in which the vertical axis of the lens is approximately vertical to the ground and usually considered to be plus or minus 5 DEGS.
Wide Angle Lens – Lens with an angle of view wider than that considered subjectively normal of the human eye (i.e. more than about 50 DEGS). Wide angles of view are characteristic of lenses with short focal lengths.
Call Warren White at 805-709-8455 to discuss your project, or email info@aerialperspectives.com