WOT: Average Resolution for Mid-80s CCTV?

Soniclight wrote on 9/24/2015, 5:35 PM

The apartment complex I live in was built in 1979 as from what I know so far, it's on-site surveillance system is deemed to be from shortly thereafter, perhaps mid-1980s. I've seen the master panel with multicam layout, it's as expected, all black and white.

I may be asked to give some feedback on if/when we get the funds to upgrade. As understand it, most current standard modern CCTV/surveillance systems use 1080p/1920x1080, My guess is that one we have is most likely based on 4:3 TV but I don't know the resolution, and so probably SD or 720 x 480. Or could it even be lower?

The cameras are placed 3 stories high (near top of building) and so the ability to zoom in on a license plate or face of an intruder would = useless.

Last, a lot of CCTV/surveillance are still monochrome/b&w and so perhaps rewiring the whole place (250+ units property) may or may not be necessary. As to encoding formats, these systems probably have their own proprietary offshoots of mp4, etc.

As stated, way off topic.
But if anyone has some experience/knowledge, input welcomed. Thanks.

~ Philip

Comments

riredale wrote on 9/24/2015, 6:03 PM

Not my field of expertise, but stuff from that era was probably based on NTSC 525 line standard. As such, vertical resolution was probably limited to about 330 l/ph and the horizontal resolution was probably similar, though if the video was recorded to tape then horizontal resolution was probably only about 220 l/ph.

Even a DV-based format would probably be far sharper.

musicvid10 wrote on 9/24/2015, 6:25 PM

300 lines, plus or minus.

astar wrote on 9/24/2015, 10:10 PM

I would say about 240 lines of horizontal resolution for VHS in 6 hour mode, which is what the CCTV cameras would have been recorded to, possibly even 4 cameras in that resolution. The only reason I remember this, was because SVHS and LaserDisc at 400 lines was a big deal.

If you are replacing the system, make sure to get a facecam at the keypad/entry way to complex. Top down overall might not be enough to get a good ID. Then all camera coverage on the entry's and fire exits. Face and license plate coverage on garage access panels, and overalls in garage, in case cars are broken into or stolen.

http://www.axis.com - is the security pros choice. When I looked into something for the house, Samsung IP CCTV (https://www.samsung-security.com/) seemed pretty cool. Even Dropcam if your system is really small, you can just get an external CCTV mount and install a dropcam inside. Sony and Panasonic also make nice professional IP CCTV systems.

Soniclight wrote on 9/25/2015, 10:39 PM

Thanks to all for feedback.
I'll have to Google and figure out what "lines" translates into pixel-speak equivalent..

Soniclight wrote on 9/26/2015, 2:26 AM

Well, here is a TVL to Pixels answer...

Source: CCTV Tips TV Lines (Analog) vs Pixels (Digital Resolution)

riredale wrote on 9/26/2015, 11:06 AM

The confusion arises because before digital sampling and CCD/CMOS imagers, TV was an analog process. Resolution was typically determined by one of those "indian head" resolution charts, with a series of converging lines oriented vertically and horizontally. At some point the lines would become indistinct from each other, though there would not be a clear point where that happened.

The term "lines per picture height" meant the number of black/white lines that could fit within the vertical dimension of the image. Resolution in the horizontal axis also used "lines per picture height" so that the horizontal sharpness could be compared to vertical, regardless of picture width (aspect ratio).

One could never get the theoretical maximum out of a given number of scan lines. A 525 system only used about 483 actual image lines, and due to various reasons one couldn't even resolve that number on a chart. The Kell Factor was a number invented to estimate actual resolution. The number generally used is 0.7, so out of 483 active lines one could actually resolve about 340 "lines."

Soniclight wrote on 9/26/2015, 11:54 PM

Thanks for the clarification though... some confusion (mine) still remains. Due to what you said, I just hope that what seems like an approximation as the comparison/translation in the chart I included is accurate enough for general, non-photonic sciences purposes. :)