3/28/2023 0 Comments Widescreen pixel tester![]() However, when using telephoto lenses, the field of view is more likely to contain relevant information. Telephoto zoom: In wide fields of view, objects at the periphery, such as trees, shrubs, walls, and other objects, are often irrelevant, adding nothing to the scene. Aiming the camera down further to compensate quickly begins to remove wanted areas from the scene, and may cut off subjects' heads, or simply not provide a deep enough FOV. This is because while 16:9 may remove potentially wasted ceiling or sky from the image, it removes portions of the scene closer to the camera, where pixel density is highest. Notice that the wide TV shot shows more details on the left and right sides while the wide CCTV shot actually loses details on the bottom.ĭowntilt: If cameras are installed with anything aside from slight downtilt, 4:3 better fits the field of view. This image demonstrates how the two applications differ: By contrast, in surveillance, you simply lose on the top and bottom. What may cause confusion is that in TV, unlike surveillance, the wide screen aspect ratio actually adds more content to the left and right side. Ultimately, this is the core of the problem. In the 16:9 you simply lose 304 rows of pixels. For example, with a 1.3MP sensor, the 4:3 aspect ratio is typically 1280 x 1024 while the 16:9 version is 1280 x 720. The only thing that differs is the height. ![]() For any given sensor, the FoV width for 4:3 and 16:9 are exactly the same. Taller Not Wider: The term 'wide' is a misnomer for surveillance applications. There are three key factors which affect which aspect ratio should be used: These sample images were produced by the same camera, in the same location, switching aspect ratio from 4:3 (1.3 MP - 1280 x 1024) to 16:9 (720p - 1280 x 720). An outdoor parking lot - with both wide and telephoto FoVs.An outdoor intersection - with both wide and telephoto FoVs.This surprised us as well but our series of tests, in a variety of real world scenes, showed over and over again clear practical benefits of 'full' 4:3 aspect ratio. Unfortunately, in practice, this assumption, while true, detracts from real world performance. there are no 10 foot tall people or 30 foot tall trucks, etc.) The premise behind 16:9 preference is that most scenes in surveillance are typically wide but not tall (i.e.
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