Line Lock

[qman 0]

Could someone tell me what does "line lock" means in a camera?

[Pat 0]

Line lock is used to synchronise multiple cameras on an instalation. If a camera is powered of AC and set to linelock the camera is triggered off the mains (line). Most cameras with line lock also have phase adjust so you can alter the point on the mains cycle that camera triggers, this is for three phase installs. Why would you use it? If all cameras are triggered at the same point in time you stop image roll on analogue switchers. Another way to do this is Genlock but that is almost never used. FYI you get a better picture in internal sync than in line lock. Look a edges of objects in line lock and you will see more colour roll (like barbers pole) than when the camera is in internal.

 

This is quite handy for explaining camera functions http://www.baxall.com/pdf/guide.pdf I could be biased as I wrote most of it! It is pretty generic.

[rikky 0]

I've seen that test equipment does exist to synchronize the camera phasing.

Is this another solution than line lock?

Has anyone used this solution?

[AVCONSULTING 0]

Line lock is almost never needed when using cameras these days since DVRs and mux's automatically take care of any out of sync signals.

[cctv_down_under 0]

It is not needed much unless on an old system

[Pat 0]

Rikky, I do not know what the test equipment is that you are refering to but at a guess if it is used to sync cameras then it sounds like a means to set line lock. The above are right that digital equipment such as multiplexers do not require the cameras to be in sync as they use framestores to line up each video source. However there are a lot of small and large matrixes that would benefit from correctly adjusted line lock.