What is life like in the Analog pre-dvr days with multi cams

[traderjay 0]

For those of you that has been doing this for a while, what is life like back in the good ole analog days before the advent of DVRs? I guess multiple VCRs must be deployed to record the footage or are there multi-deck VCRs that can record to multiple VHS tapes at once? Cabling must also be quite painful too I guess?

 

So for a site with multiple cameras, multiple VCRs must be used and someone has to frequently change the tapes as they wear out quite quickly with 24/7 use and VCR head cleaning? Maybe you guys can share some pictures of ancient setup for us newbies to relish on how far IP Surveillance has progressed

[Daryl733 0]

Swicher - Switch between cameras at interval. you'll miss out action when it switch to other cameras.

 

Multiplxer - Allows combining of multiple cameras feed to the VCR.

Cheap will just do multiple display and record the same display to the VCR. You'll play back the same display, so each camera occupied only part of the screen. more camera, smaller. Live multiplexing was more expensive, so that's why the older one normally have different FPS. Cheap one less fps. Better one live.

Better one will cycle through the cameras and store each one with whole frame. When you playback, the VCR output will goes through the multiplexer again to combine everything and also allow zooming in to each camera to view full screen, etc. However, due to the recording method, you can never achieve live FPS. It's normally only ard 25fps (or 30fps for NTSC) divided by the number of cameras you have. 16 Channels Multiplexer can only record at ard 1.5fps.

 

VCR are time lapsed. You can use a 240mins tape to record for 24 hours, or even up to 1 week on some models if i remember correctly. They'll turn the tape slower to record. Quality is sacrificed for the length of recording, like how we set the compression quality on DVR nowadays. You got to change tape regularly and have multiple tapes to cycle through.

[traderjay 0]

Swicher - Switch between cameras at interval. you'll miss out action when it switch to other cameras.

 

Multiplxer - Allows combining of multiple cameras feed to the VCR.

Cheap will just do multiple display and record the same display to the VCR. You'll play back the same display, so each camera occupied only part of the screen. more camera, smaller. Live multiplexing was more expensive, so that's why the older one normally have different FPS. Cheap one less fps. Better one live.

Better one will cycle through the cameras and store each one with whole frame. When you playback, the VCR output will goes through the multiplexer again to combine everything and also allow zooming in to each camera to view full screen, etc. However, due to the recording method, you can never achieve live FPS. It's normally only ard 25fps (or 30fps for NTSC) divided by the number of cameras you have. 16 Channels Multiplexer can only record at ard 1.5fps.

 

VCR are time lapsed. You can use a 240mins tape to record for 24 hours, or even up to 1 week on some models if i remember correctly. They'll turn the tape slower to record. Quality is sacrificed for the length of recording, like how we set the compression quality on DVR nowadays. You got to change tape regularly and have multiple tapes to cycle through.

 

Hey Daryl - thanks for sharing your experience from the old days If IP cameras weren't around today, I wouldn't have be able to install my own Avigilon system for the home! The old days sounds like a complete nightmare and I wonder how many court cases were lost of prosecution failures due to unrecognizable subject.

 

Btw you are from Singapore? I lived in that beautiful country for 5 years and I gotta say, the high humidity there is the ultimate test for CCTV camera. I had so many electronics fail (TVs, Cameras, CD players etc) over the year due to humidity and corrosion. Any substandard cameras will quickly die

[survtech 0]

Not necessarily. When I started my job in the latter 90's, we had around 500 VCRs recording 8 hours on T-160 tapes in SLP and a few others recording the signal from 16-channel multiplexers, also at SLP speed. While the customers at my previous job did use either time lapse or 24-hour "Real Time" VCRs, the casino business was required by law to record at least 20fps, which coincidentally was the frame rate of 24-hour Real Time VCRs. We chose to record 8 hours at SLP and change tapes three times a day (once per shift) since Real Time recordings were lower in quality.

 

Note, we didn't have to actually replace tapes that often. They were good for many record/rewind sessions, as long as they were handled properly and the VCRs were kept clean. That was one of my jobs: cleaning and repairing VCRs. I say record/rewind sessions because the vast majority of tape recordings were never played back. Recordings were mostly retained for a week, then overwritten with new recordings.

 

Real Time recorders also cost more than the consumer-grade VCRs we installed in 1999. After testing a number of brands, we settled on the Mitsubishi HS-U445/446/447/448 models.

 

Of interest, by the time we switched to NVRs in 2003, it took two people 4 hours to prep, change, rewind and file the tapes from the over 700 VCRs we were up to.

[Daryl733 0]

Yup. From Singapore.