Comments on: Technical question about security camera…what angle lens do I need? http://losangelessecuritycamera.com/2009/11/26/technical-question-about-security-camera-what-angle-lens-do-i-need.html The Secure Choice Fri, 12 Mar 2010 06:23:55 -0700 http://wordpress.org/?v=2.8.6 hourly 1 By: LEM http://losangelessecuritycamera.com/2009/11/26/technical-question-about-security-camera-what-angle-lens-do-i-need.html/comment-page-1#comment-2055 LEM Thu, 26 Nov 2009 07:38:00 +0000 http://losangelessecuritycamera.com/2009/11/26/technical-question-about-security-camera-what-angle-lens-do-i-need.html#comment-2055 There is not enough detail to tell. The focal length of a lens alone does not give any information as to what field of view it will have at 30ft. It is also necessary to know the sensor size to be able to tell. Or if the camera or lens specs have angle of view, that's even better. A different sensor size behind same focal length lens will produce different angles of view. The bigger sensor, the smaller angle. If you know the angle, you can use the simple geometry to figure out the field of view of a camera. This article may help explain what it is: http://en.wikipedia.org/wiki/Field_of_view Also this one: http://en.wikipedia.org/wiki/Field_of_view The only thing I can tell you, is that 6mm is going to be twice as close view as 3mm. So 3mm is a wider view, and 6mm will be more of a close-up (given both have same sensor size). But if you get too wide, you lose details, if you get too close, the action may happen outside of camera view, or faces get cut-off. That's all I can tell from available information. Sorry couldn't help you any further without the extra data. LEM. There is not enough detail to tell.

The focal length of a lens alone does not give any information as to what field of view it will have at 30ft. It is also necessary to know the sensor size to be able to tell. Or if the camera or lens specs have angle of view, that’s even better.

A different sensor size behind same focal length lens will produce different angles of view. The bigger sensor, the smaller angle.

If you know the angle, you can use the simple geometry to figure out the field of view of a camera.

This article may help explain what it is:
http://en.wikipedia.org/wiki/Field_of_view

Also this one:
http://en.wikipedia.org/wiki/Field_of_view

The only thing I can tell you, is that 6mm is going to be twice as close view as 3mm. So 3mm is a wider view, and 6mm will be more of a close-up (given both have same sensor size). But if you get too wide, you lose details, if you get too close, the action may happen outside of camera view, or faces get cut-off. That’s all I can tell from available information. Sorry couldn’t help you any further without the extra data.

LEM.

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