Posts

Showing posts from October, 2014

Converting CCTV lens from video auto iris to DC auto iris

Image
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 auto iris, that is the standard…