There are 3 controllable rings on the CCTV lens. Each ring has 2 characters on them with the ring farthest from the sensor being F and N. Next is O and C. The last ring is T and W.

What does each of these characters represent? The O and C controls the aperture, so I'm assuming it stands for open and close. I'm guessing the F and N stands for far and near. I have to adjust that and the W and T ring for the camera to focus.CCTV Lens


2 Answers 2


"W"ide and "T"elephoto - i.e. they will control the zoom - as opposed to "N"ear and "F"ar which control the focus.

  • 12
    \$\begingroup\$ O for Open, C for Closed? \$\endgroup\$ Commented May 31, 2023 at 20:02
  • 2
    \$\begingroup\$ I believe so. The diaphragm opens up and closes in relation to that particular ring. \$\endgroup\$
    – Neoprism
    Commented May 31, 2023 at 20:25

The descriptive text on the lens says "2.8-12mm" so this is a zoom lens. Therefore you have three controls, aperture, focus and zoom.

I would be pretty sure that the markings are

  • Wide/Telephoto (zoom)
  • Open/Closed (aperture)
  • Near/Far (focus)

On most lenses there is some cross-coupling between the focus and zoom. Changing one will have some effect on the other.


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