A lot of the related questions require variables that we simply do not have. I would like to calculate sensor size for a video camera. We have focal length and resolution but I do not know the field of view or crop factor or any other additional camera information. Is there a way to calculate just from this? If I have to have something like field of view angle, can I calculate this without sensor size and then use it to find sensor size?

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    \$\begingroup\$ Does this answer your question? How can I calculate sensor size (width and height) from focus length, vertical, and horizontal angle of view? \$\endgroup\$
    – mattdm
    Commented Dec 16, 2019 at 22:54
  • \$\begingroup\$ No. This requires knowing the angle of view. I do not know this. If there is a way to calculate this so that I can then use that to calculate sensor size, that would be helpful. \$\endgroup\$
    – user89092
    Commented Dec 17, 2019 at 2:20
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    \$\begingroup\$ Why do you need the sensor size? How exact does it have to be? Have you tried looking up the specs online? Is the camera capable of taking stills? \$\endgroup\$
    – xiota
    Commented Dec 17, 2019 at 2:31
  • \$\begingroup\$ Yes, it can take stills. Can I get sensor size from that? Unfortunately, the camera is a cheap amazon model and I cannot find specs for it and the seller won't respond. Sensor size is a requirement for a specific set of software used for analyzing video. \$\endgroup\$
    – user89092
    Commented Dec 17, 2019 at 2:36
  • \$\begingroup\$ Have you tried taking stills and looking in the Exif? There should be adequate info to approximate sensor size. (focal length and 35mm equiv focal length) You can use trial and error from there to find settings that work with your video analysis software. More accurate info may be in the lensfun database if your camera and lens are supported. \$\endgroup\$
    – xiota
    Commented Dec 17, 2019 at 7:23

1 Answer 1


You cannot calculate sensor size from just focal length and resolution. Since resolution can vary depending on the sensor's construction, this just plain is not enough information.

If you have a scientific application, you should buy parts where the specifications are known. If it doesn't matter that much, you can measure the angle of view in practice from sample images of known objects, and then, since you know the focal length, work back from there.

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    \$\begingroup\$ "sample images of known objects" - such as measuring sticks. \$\endgroup\$
    – xiota
    Commented Dec 17, 2019 at 7:27

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