Cooperman

Hey Thomas, rather than a housing, you'd probably be better off with an igloo As it happens, I had to design a 'pod' camera system some years ago for use in the arctic circle. The camera / lens will need to be maintained at a reasonable temperature to at least guarantee reliability, and if at all possible, you'll need to look at fitting sealed camera housings with highly rated multipole connectors, so that the complete camera assemble can be simply unplugged (provided it's not frozen!), for easy service exchange. I vaguely remember that some of the U.K. manufactured Pan / Tilt heads were offered with special heater / lubricant packs for specific use in arctic conditions. I would imagine companies like Pelco and Cohu would be worth a call, on your side of the pond. It might also be worth making a few enquiries with some Canadian based specialists. Final thought, but do you know if there are any special regs. for using cameras in a gas terminal?

kaysadeya, The VCB 3512 / 3524 cameras are very good overall, although in comparative tests, I used to prefer the 1/3" VCB 3372 (3374) in terms of overall performance. That said, I've only used the 12v CCIR versions, which may differ from the EIAJ versions you'd use stateside. Last I heard, the VCB 35** were being discontinued, so if the 3384 is a replacement for the 3374, I'd be inclined to suggest you go for that one. Whilst it is a 1/3" camera, try and use a 1/2" (or 2/3") format lens then you'll get the best out of the camera. As rory said, the VCC 4592 / 4594 Day Night model is a really nice camera, but a lot more pricey. Interestingly enough, I had a sneak preview of a new Sanyo model last week, with menu selectable Wide Dynamic function. Not sure when it's due out though.

True

quote VST_Man The only obvious problem here might be if the design of the PSU uses four 1 amp regulators, one on each output. If you change the fuse on one rail to 2 amp, the regulator will give out before the fuse. However, if the PSU has a 4 amp regulator with the output split to four fused connections, then the fuse change would not present any problem.

Many thanks for that C7 in CA, Never come across that one before (I've led a very sheltered life). I suppose the modern equivalent would be pyro cable, where the live and neutral are mineral encased inside an outer copper tube. Fortunately, it's not the kind of cable we need to use too often for CCTV work. hey herminshs, Go easy on the knob jokes, it's not good for the blood pressure

erm, isn't that what D3Data provide? (banner ad at the top of the page)

antdickens What your are trying to do (current sharing) will work in principle, but ... some heaters will pull more current when they first start up, and as you are looking at a total load of 4 amps against a 4 amp rated output, there is nothing in reserve. Depending on the build quality, the PSU may well be operating on its limit, and this may significantly reduce its life expectancy. If I'm asked to spec a PSU, I generally try and under run a unit by at least 30%, so that it's never being worked too hard. If at all possible, I would always prefer to keep the heater and camera PSU's seperate, particularly as the camera is the more critical piece of kit. Also you don't need a regulated supply for a heater; unregulated is fine. If you lose a heater supply for a couple of days, it's generally no big deal, but if the PSU fails and your cameras go down, that can be more of a problem

Hey guys, I know I really shouldn't ask, but what the heck is 'knob and tube'. On behalf of any other Brit colleagues that are chuckling their socks off in blissful ignorance, I should perhaps mention that the term 'knob' does have quite another meaning, this side of the pond

Good point

Seems a rather excessive (and expensive) way of solving the problem. You would have thought the mere fact of being observed on CCTV ( using a static camera) or catching them at it using a covert installation, would be far more effective. Maybe we are less phased by CCTV cameras over here - four and a quarter million and counting ....

squale, As Thomas said "PTZ's are great if you will be monitoring 24/7. If not then four cameras may be the better option." I couldn't have put it better myself. Many PTZ cameras are installed for all the wrong reasons, they're great fun, but generally should not be used in place of statics, but preferably in support of them. Good luck with the fixed cams.

Installing it is not a pain (if you pay somebody to do it for you ). If the cable is handled correctly, it's no big deal, but it does require a bit of practice and common sense to terminate the cable. Mind you it's a heck of a lot easier than it was twenty years ago. At that time, the glue that's used to fix the fibre inside the connector, took 24 hours to cure, then the fibre had to be parted off with a diamond tipped tool, before it was hand polished using various grades of lanishing film. The first time I did it, it took about 90 mins to do one connector, and I had 64 to do! Now that was a week to remember.

English soccer supporters are like elephants, they never ever ever forget ..... Here's to the next 10,000!

In the good old days amplified co-ax over those and greater distances was quite common, but with the cost of equipment and cable now, it would be daft to look at using that approach. As you say rory, amplified UTP is more appropriate, although if there are a number of signals, or a mixture of video / audio / control, then fibre optic would be well worth considering.

Looks like you guys have the same old problem, quite legal to buy it, but not legal to use it

If the PTZ is being used a short distance from the monitoring position, then direct drive using a multicore cable is the cheapest option; you can then use a spare pair(s) for the camera power supply, so only two cables needed, multicore for control (inc. Power) and co-ax for Video. Telemetry control sending signals up the video coax is generally much better suited to longer distance or multi camera operations. The choice of P/T motor (i.e. AC or DC) is generally based on requirements. For variable speed operation most modern heads use DC motors, whereas for constant speed operation, syncronous AC motors are far more efficient and stable (i.e. their speed is dictated by the mains reference, either 50 or 60 Hz).

I hope this is fitting BNC connectors that you're talking about Funny, I thought it was only the Swiss that did that

http://www.mobotix.com For anyone that's interested in the U.K., they have a stand at the IIPSEC 2005 show at Stoneleigh Park (it finishes tomorrow).

ah, paranoid by name and ......

me too, and ditto

paranoid, IR bouncing off the grass doesn't sound bizarre at all, that's exactly what it's doing. The chlorophyll in green leaves is highly IR reflective, so foliage in general gets lighter, and grass in particular can often appear like snow, particularly when viewed at slightly higher IR frequencies (850 - 1000nM). A couple of suggestions for you. Certainly try VST_Man's idea of removing the lens cover - only thing is at the moment it's a bit damp and chilly during the night in Old London Town, so best wait until their is no frost, sleet or snow. If you do open the camera at this time of year, you'd be advised to stick a small packet of 'silica gel' inside, and that will hopefully soak up any internal damp. One thing you can try without opening the camera is to reduce the IR output and see if the problem improves. If you can get hold of some very fine metal mesh (you used to be able to buy it in car spares shops, it's used for lining rust holes before applying filler!), simply cut a circle to fit the front of the camera, and then cut a small circular hole for the lens to look through. Just for testing, make sure the cameras front window is clean, then tape the makeshift mesh attennuator in place, making sure the lens is not obstructed. If it works, then you can look to fit it permanantly inside the camera. Another possibility is to try a small polarising filter (available from any good photographic shop) between the lens and the front glass (if there's room). this will cut down the effect of any reflections on the front 'window'. Then again VST_Man may well be right about the quality of lens fitted. If the problems are caused by excessive internal reflections in the optic, the only way to get around that one, would be to change the lens for a decent one. By the way, whereabouts are you in London?

paranoid, A few silly questions for you. Is the camera mounted outdoors, or looking out through glass from inside the building? If it is indoors, does the window have double glazing? Also, do you have the same lenses on every camera? If you've mounted the camera to look out through a 'porthole', are you sure the IR diodes are not reflecting off the glass? Told you they were silly questions

Hey Rory, agree with you on the matrix description. The only thing is that this side of the pond, a Video Distribution Unit is not a switcher or Mini Matrix. In general, it is used to split (normally described as a Video Distribution Amplifier or VDA) a single or possibly two Video Input signals, and then pass them through to a number of output sockets, usually 3, 5, 6 or 10. If you combine a number of VDA's with a number of switchers, this will in effect form the building blocks for a basic 'Mini Matrix'; mind you, doing it this way it can get rather expensive very quickly

In general, if you choose an 'Alarm' input switcher, the simple principle is that when you ground the corresponding channels alarm input, it will then switch to that channel, and most will stay on that setting until reset or another alarm input is triggered. So for example, pin 3 (or terminal 3) connected to Gnd. or Common will make the switcher lock on Video In 3. If the output from your switching device is simple 'dry' relay contacts, that would work fine. If the switching output is for example +12v DC, then you can connect up a small external relay to do the switching for you. If push comes to shove and you simply can't get hold of an alarm input unit, most standard selector switches can be hard wired across their contacts (16/0.2mm wire for a short distance) to effectively remote that switches function. The conductors can then be 'closed' using a small external relay driven from your trigger device. The only reason I suggested the possibility of a PIP, is that as well as being able to reverse the insert under external alarm input control (i.e. the small picture becomes full screen or vice versa), if I remember correctly, some PIPs will also allow the inserted picture to be removed under an external alarm command ( so you could have the option of PIP view, or full screen of Main picture, or full screen of Insert picture ). Costs a lot more than a switcher though

loop, Any alarm input switcher should do what you want, but you may find it harder to get hold of 2 channel units, rather than the more common 4 channel. One manufacturer here in the U.K. has a 2 in, or the option of a 4 input at the equiv. of about $5 more. I would imagine that US sourced gear is probably more readily available where you are. Maybe other guys will have a few suggestions for suitable models. One other possibility might be a picture in picture (PIP) unit, then you can connect all five at once.