View Single Post
  #74   Report Post  
Old September 17th 17, 07:05 PM posted to uk.railway,uk.transport.london,misc.transport.urban-transit
Charles Ellson[_2_] Charles Ellson[_2_] is offline
external usenet poster
 
First recorded activity at LondonBanter: Sep 2012
Posts: 498
Default Explosion on district line

On Sun, 17 Sep 2017 09:40:01 +0100, Roland Perry
wrote:

In message , at 03:29:35 on
Sun, 17 Sep 2017, Charles Ellson remarked:
But instead of the early grainy, very low res, fuzzy, extended play VHS
images on worn-out tapes, it's now HD quality, sharp, clear, digital
images. Perhaps some are now 4k video quality?

How many would sir like ?
https://www.cctvcameraworld.com/4k-ip-cameras.html

I wonder how widely installed those are? Most installed cameras are well
behind the state-of-the-art.

At around 200 squid a time possibly roughly the same good/bad quality
spread among users applies as before when it seemed to be "TV" quality
v. something cheaper ?


The cost of CCTV systems is much more than just a consumer grade camera.
For public surveillance not only is there the backhaul, but they are
often able to pan and tilt, and need much better sensitivity/
illumination than those listed.

Have you actually installed and used those cheapo ones? They are OK for
the passageway down the side of a shop, but not much else.

There's not much point having pan and tilt if you haven't got someone
to operate it; the "do you know this person?" pictures generally seem
to come from fixed cameras. The need for moveable cameras is reduced
by siting fixed cameras at pinch points; each moveable camera is
likely to augment several fixed cameras depending on purpose. When you
get to the point of needing to track a specific target then you
probably are needing more moveable cameras (and zoom lenses).