Thursday, May 3, 2012

Sensor sizes explained

Matching a lens to a camera is a headache. The problem is in finding a lens that will put the whole area viewed – the field of view – onto the camera sensor. If sensors were all the same size life would be simple, but unfortunately they aren’t. If you look at the specs you’ll see them referred to as 1/3”, ½” and so on, but do you know what this means?

Brian Robertson of PPT Vision recently posted one of the best explanations of this that I’ve ever read on the PPT blog. “Machine Vision Cameras and Imager Chip Sizes” (April 18th, 2012,) provides a concise explanation of why sensors are described in this seemingly archaic manner. It also helps clarify what a 1 1/8 sensor actually is.

Once you understand what the numbers mean selecting a lens becomes a little easier.

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