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Issue link: https://securitysales.epubxp.com/i/166764
the attention to this dependency to be overlooked, with the idea that camera misalignments or scene issues can be accounted for by later adjustment of the variable focus feature of the lens. Tis is a mistake and a potentially costly gamble. You should go into your design considering each aspect, including a f xed FOV, and its dependency on the other setup variables. Brush up on your geometry, fnd and use a FOV calculator and a good camera layout tool. Make sure you verify your detection scenes, overlap your camera coverage for blind zones and defne your FOV settings so you have some wiggle room after the equipment is installed. Tere will be inaccuracies in pole placements and unforeseen scene issues, but you shouldn't count on a varifocal lens adjustment to be able to accommodate. Tere is almost no security application where viewing the sky has any value. However, there are many reasons why you should not look at the sky. Tese include items such as glare and blinding the camera during sunrise and sunset. Another consideration is the idea that you are essentially wasting 33% of your video storage and network bandwidth on the interesting cloud formations. Te only reason to have sky in your FOV is to give a point of reference and ensure you have enough room for any vertical detection zones. As a general rule, 10% of the scene is more than enough to give a frame of reference. When considering vertical detection scenes, for example ensur- 2. THINKING LIKE A PHOTOGRAPHER We all remember our high school photography class and the rule of thirds: two-thirds of the scene should be ground and subject; one-third should be reserved for the sky. We never seem to get it right when we're taking photos of Aunt Beatrice or our vacation photos from Hawaii, but it's amazing how many times we get it right when setting up security cameras. Although the rule of thirds is pleasant to the viewer's eyes, in the security world, it does not apply. The effectiveness of your security camera is highly dependent on the proper setup of the camera's feld of view. SEPTEMBER 2013 / SECURITYSALES.COM / 141 PHOTO: ©ISTOCKPHOTO.COM IMAGES AND CAPTIONS; ALL COURTESY PURETECH SYSTEMS nce Sins