GrouchoBoucho

Im thinking of upgrading my analog cctv system and im wondering which is the best to go for IP or HD SDI?

what do you guys think ?

 

If you have existing coaxial runs, SDI is the way to go.

assuming your old cable isn't crappy or damaged... and assuming it's actual rg59/rg6 coax rather than the little thin all-in-one bundle that came with your old costco kit.

it's probably because the bnc out is 640x480 composite video, which your tv is then up-scaling to its own resolution, and stretching to fill the screen. this is to be expected.

any m12-type lens should work, but do yourself a favor and get real cameras.

no.

^op is in canada

hahahahahahahahaahahahahahahahaha

Certainly the effect is not present when it is zoomed out most of the way:

yes it is, it's just not as noticeable. if you had a high enough resolution camera and you zoomed into the image digitally, you would see it as well.

If this is an atmospheric effect, can anybody put a name to it?

http://lmgtfy.com/?q=heat+ripples

Can you toggle WDR/Lightfinder on a schedule?

yes you can. the 3384 lets you toggle modes based on a number of triggers, including schedules, and external inputs. the only thing it doesn't do is trigger based on light level... at least, not directly. it *will* let you toggle when the camera switches between day and night (icr) modes; however, in one particular situation, i found this a bit tricky, because the camera would switch to night/b&w/icr-out, then the lightfinder would kick in, the picture would get brighter, and it would then switch back to day/color/icr-in, which in turn would trigger the switch back to wdr, at which point the image would get dark enough again to initiate the switch back to night mode... and on it would go, all night or until the ugly lights came up.

i could have tweaked exposure levels to avoid this, i'm sure, but i found it just as easy to program a schedule into the camera (you don't have to do it through a url). i have a dozen or so of these in a restaurant/lounge using wdr in the day and lightfinder at night (when the lights dim down), and they're spectacular.

rg6 and rg59 are both 75 ohm impedance and fine for cctv. crimp-on f connectors and an f-to-bnc adapter will also work fine. and yes, i know this from experience.

you *don't* want to use a 50-ohm cable like rg58, though.

more important is that you use cable with solid copper center conductor (not copper-clad steel), and 95% or better braided copper shield (not foil-and-drain-wire).

Hi all -

 

I have Sercomm OC821 outdoor IP cameras that were included with my home security bundle. Their motion sensitivity is driving me crazy, giving several false alarms every hour. My post isn't so much to figure out why these cameras are so sensitive, but more to understand how PIR cameras in general work, and in turn help me experiment on ways to reduce the false alarms. For example, I have one camera looking down on a driveway, and still gets many false alarms even when there's clearly no activity on the driveway.

are you sure it's the pir triggering the alerts and no video motion detection?

I understand at a high-level how PIR sensors work (this site was awesome: http://www.ladyada.net/learn/sensors/pir.html), but one thing I can't get an answer to is what the PIR sensor's field of view is, and whether or not it matches (I doubt it does) the field of view of the camera itself - which I think might be part of the problem, as there might be things outside the field of view of the camera that could still be setting off the PIR sensor.

since alerts are so frequent, have you tried simply watching the area out the window, to see if there's something happening that's setting off the pir?

Does anyone know roughly what the field of view is for PIR sensors? The lens on the camera supposedly has a 66 degree view angle, which is pretty narrow. I'm just trying to figure out if the PIR sensor needs its view angle cut to match the view angle of the camera.

there is no "universal" fov for pir sensors; pirs have "lenses" as well, to control the fov. that's what that little white plastic bit is over the sensor.

(I'm asking all this, since the seller of the wireless video transmitter, told me that I couldn't hook the transmitter up to a cable attached to a BNC jack on the DVR. He's convinced that the video won't go from the RCA jacks, through the coax cable, and into the BNC jack on the DVR... This I find odd, so I'm posting here, trying to find out what's true!)

this seller has no clue - i would avoid buying from him for that reason alone.

i would also be surprised if you actually got a solid, reliable video feed over that 300m.

buy an 8-channel dvr - problem solved.

I wanted to build my own server for it, so I could have extra space. I was going to go with a FreeNAS server. It's like RAID5, but better (and faster).

okay, the next step there is, you need to either add nvr software to it, or you need cameras that can write directly to network storage.

when you say "each building has a separate super speed internet connection", keep in mind that the *upstream* speed is as important as the downstream, because the each building's cameras have to be able to *send* the data out. a typical high-speed internet connection may be 50mbps down, but under 5mbps up... a single 2mp/1080p camera can easily eat up to 8mbps; that camera would saturate the outgoing connection all by itself.

remember that internet providers usually have a maximum amount you can transfer per month, too. 8mbps is 480mbit *per minute*... 28.8gbit per hour... over 690gbit or 86gbytes per day. if your service has a 500gb/month cap, you could potentially hit that in less than six days. with *one camera*.

"up to 100m" yeah... riiiiiiiiiiiiiiiiiiiiiiight

Why not go with IP cameras ...

sounds like he already thought of that:

i want to be able to access a remote cctv camera which has a built in vpn client

i would never trust someone on a website to give an accurate quote for a business that *really* requires a site visit first.

why is cat5 not an option?

connect through a router that supports dd-wrt - that has both vpn client and server functions.

i'll give you one solid reason: there are still a few uses for which there aren't suitable ip cameras available, at least not at a reasonable price. i have installs where good *low* light performance is necessary - i mean *low* light, with no ir. there are particular analog cameras that work exceedingly well for this. there are no ip cameras i've found that even start to come close until you get into a particular 1mp model at about 6 times the price. i'd love to do all-ip because there's so much more flexibility, but the products simply aren't always there.

better yet, upgrade to an ip system and plug the ptz into an encoder.

no - i was making sure you weren't doubling up, as that will negate the noise-rejection properties of the cable.

next question: are these actually baluns, or are the ebay junk that *claim* to be baluns but aren't?

do they look like this?

are you using one pair of the cat5, or two, for the video?

1.- Do I need to configure the ip cameras with ip addresses...

yes; cameras are just like any other network device.

2.- Since this new installation requires at least 500 feet of coax cable, do I need a device to bring the video signal from one end to the other end ?...

Next why do you want to run over coax? Why not just run new CAT5e with a POE switch or a POE injector? This will allow you to transmit the video and the power down one cable.

you can only run ethernet for 100m/330' over utp.

yes, you can use coax, via ethernet-over-coax adapters. there are several different brands out there; i've recently been using altronix ebridge adapters quite successfully. they make a version that will send poe over the coax along with the ethernet.

3.- How I'm going to power the cameras ?

if you're replacing existing cameras and re-using their coax, you can use the existing power (usually - check voltage requirements). if you're putting in new runs, you can pull a power cable along with the signal line... or use power-over-ethernet (poe).

I would like to find a good system for putting all these ip video cameras over coax....Any suggestions ??

 

Thank you for any help....

again, eoc adapters... but unless there's some *specific* reason to do this (like the distance factor), stick with cat5e. it's cheaper (*much* cheaper if you factor in the cost of the eoc adapters), and far easier to work with.

remember that the cable technically isn't carrying video... it's just data on the network. imagine it like youtube, streaming video to your browser - an ip camera is a similar idea, digitizing the video and sending out a video stream, that the nvr or vms software receives and records.

i've used rs232 to run ptzs at well over 100m

http://en.wikipedia.org/wiki/RS-232#Cables

The standard does not define a maximum cable length but instead defines the maximum capacitance that a compliant drive circuit must tolerate. A widely used rule of thumb indicates that cables more than 50 feet (15 m) long will have too much capacitance, unless special cables are used. By using low-capacitance cables, full speed communication can be maintained over larger distances up to about 1,000 feet (300 m)

http://en.wikipedia.org/wiki/RS-485

Maximum distance 1200 metres (4000 feet)