Security Camera Interlaced versus Progressive Scan

by Johnny
(Ohio)

Question:

When speaking of images per second, most people equate that to two images needed to produce 1 frame per second. That is fine for interlaced monitors and cameras. (720i) What about progressive scan technology? (720p) Does it still take 2 images to produce 1 complete frame? I thought Progressive Scan was more efficient with motion than interlaced and that is why flat screen televisions are almost all now progressive scan.

Answer:

As you mention cameras and monitors can be progressive or interlaced. It depends on the technology.

Almost all security cameras are interlaced. It takes two scans of the image to make one full frame.

There are some that are progressive scan as well that can help when you are trying to capture higher speed movement. For most applications it is not really needed.

Typically you see CCTV recording setup to record at only 10fps so having progressive scan is not a big deal.

For monitors there is a lot of confusion out there on what the screens are actually doing and I don't want to really go into all of that.

Basically though for viewing things like sports it is best to view with progressive scan.

Thanks,

Peter Brissette
Security Camera Expert