VK4ZXI

  Converting CCTV lens from video auto iris to DC auto iris Summary It seems relatively easy to convert a video auto iris CCTV lens to DC auto iris and for a modern camera to control the lens correctly. I was able to convert a sophisticated expensive CCTV lens to DC auto iris, which otherwise was unusable.    However, I give no guarantee that it will work with any other lens, although I think the principle is the same.   If camera control is not possible or desired, it is possible to at least open the lens's iris with a voltage through a series resistor applied to the drive motor with the correct polarity. The problem I had bought a Pentax motorised zoom and focus lens for use in my amateur TV studio with the idea of using it on a remote-controlled tripod as part of a one person operation. Motorised lens are not cheap ($600), but I bought a new, but old stock, lens cheap (<$100).   The main problem was that the lens used video auto iris, rather than DC aut