Field of View Calculator

cctv-lens-calculatorsRemember the lens calculator wheels made out of cardboard?   You could select 1/4 in., 1/3 in or maybe 2/3 in. sensor, then spin the wheel to the field of view you needed, and then read the lens size you needed.

Now there are many more sensor sizes available, especially with megapixel sensors.  Luckily, most manufacturers provide the lens angles, so you don’t need to calculate this.

All you really want to do is figure out the field of view at a certain distance, based on the lens angle.  To do this, you can use a trig calculator.

Here’s How You Do It

lenses for IP camerasBefore you select the IP camera lens, make sure you understand your expectations.  It is important to first know the objectives for each area you are viewing.  Do you want to identify a person’s face, a license plate, or just detect a person walking far away?  In general, the more detail you want, the higher the resolution you need.  Once you decide what you need, you can select the lens and resolution of the camera.  The camera and lens could be different for each location.

Take a look at our article, Calculating What You Can See with Your IP Camera.  This article reviews how to use trigonometry to calculate the lens angle you will need to achieve a specific field of view.

FOr more information about selecting the right lens, take a look at Selecting the Right Resolution and Lens for the IP Camera System.


If you need help with these calculations, don’t hesitate to give us a call.  We have a lot of experience with IP camera systems and can help you get the exact surveillance system you need. Contact us at 914-944-3425 or 1-800-531-1658 (in the USA), or just use our contact form.