Cooperman

DVR Expert Australia, Did you hear a scream? I think mitt just put his hand on that searing hot PSU Sorry ..., it would be interesting to know what cameras are being used though. It certainly sounds like it may be a voltage drop problem, but then if it was, you might expect to see a slight difference in the effect between the 30' and 220' cable runs. The description actually sounds like some kind of attenuation problem, maybe double check that the cable is actually RG 59, and not some grotty cheapo import. If any single camera is connected to a monitor with a short test lead, no other cameras powered up from the PSU, and the problem still persists ... send the cameras back. Unless of course, it's the monitor!! Unfortunately, if I try and bring up the .avi test recording, I just get a blank window. Any chance of a JPEG, mitt?

In a word, spread the load - sorry that's three words. Depending on the material (and the camera), you need to look at fixing on a board or plate, and then spreading out the boards fixings over a wider area (less risk of stress fractures). Some materials can become more brittle with the effects of age, so it is not unheard of that a camera decides to abseil, with the first decent gust of wind, or build up of snow. If the longterm material strength is in question, it may be worth fitting an independent 'lanyard' cable, so if the worst happens, the camera won't end up on terra ferma.

You only tend to notice the distortions with wider lenses, when an object is placed close to the camera. In practice, you're more likely to get some distortions from the TV itself. CRT (Cathode Ray Tube ) linearity can be very variable, but on many TV's their is some distortion present which you just don't really notice (if you point a camera at a scene with vertical and horizontal lines in the view, you'd be amazed at what actually appears on screen). Just a suggestion, but whatever camera you do eventually fit, maybe place it to the side of the TV (or possibly below), then it won't be affected by the heat rising. You could use a 'dome' camera on the wall, but apart from being more restricted on lens choice, many domes use basic board cameras inside, and unless you buy a really good one, the camera / lens combination may not provide the quality of picture you're looking for. Also, if musicians are smoking (is this possible ) over a period of time, the domes plastic cover will begin to suffer. Ideally, you need to have a demo from a local supplier ... unless of course you happen to be passing

Just as well I asked nate, it wasn't such a stupid question after all. I quite liked your description that 'they are in a neighbourhood that has caused a bit of concern lately'; I suddenly had a mental picture of unsettled cows in a "larson' cartoon. Anyhow, back to the problem in hand - you need to consider what the perceived risks are if you want to put togethor a really top notch system; having said that, if you simply want to watch areas, that's not a problem. If your budget will stretch to it, high resolution ( 460 - 520 lines ) Colour / Black and White would probably be ideal. If money's tight, high res. black and white would ensure you've got decent night coverage. Ideally you will need to consider perhaps three zones; the outer, being the perimeter of the site, the external being the area around the building/s, and the internal, being the areas indoors where their may be risks to assets and personnel. Obviously you'll have to weigh up the risks, and decide what you want to keep an eye on. If you're not sure about any aspect, you can always post more information and requests, but hopefully others will put forward their suggestions on suitable equipment which is available Stateside. It might also be worth considering using some basic grade equipment in the animal recovery areas; that covers both the 'animal welfare' and preventing ' 'malpractice suits' as part of the overall scheme. Just a suggestion.

hi timmcallister, Apart from Rory's comments on various cameras (most of which are not available on this side of the pond), you mentioned you would like to use colour if possible. Whilst light levels in recording studios are generally subdued, you still need enough light to be able to see what you're doing, so I can't see any reason why you shouldn't have your wish. If you choose a half decent low light (preferably 460 lines+ resolution) 1/3" CCD camera (conventional case), you can set it to Electronic Iris, and fit a wide or preferably ultra wide Manual Iris lens. Using a quality 2.8mm optic, the whole of the square studio will be on screen if the camera is mounted in one corner at around 7 feet frm the floor. Whilst you said you don't actually need that much coverage, their is a good reason for looking at this type of lens. With an ultra wide, the depth of field is so large, that even at maximum aperture, the whole of the room will be in focus. Lighting permitting, if you can manually close the iris one or possibly two f stops, this will further increase the image clarity (ideally you want to try and exclude lights from the camera view). It shouldn't be a problem taking in more of the room, particularly as you are intending to use decent size TV screens. If the monitors were smaller, I'd suggest a narrower lens. From previous postings on other subjects, I would guess that you could get something half decent within your budget. Also if you need to change the camera set ups in the future, it's relatively easy to buy a new lens.

Hi nate, At the risk of asking a really stupid question, could you just confirm whether the cameras are required for 'animal welfare' or 'site security', or perhaps a combination of both. I'd assume it was to keep an eye on the animals, but then I know it's safer never to assume anything in this line of work. If you are monitoring the animals, what are they, and what size of areas do you need to watch (can the shape of the areas be modified / adapted to accommodate camera angles)? Also what type of lighting are you working with? The more information, the better.

Hi paranoid, You're quite right, 25 frames per second is 'real time' here in the U.K. 15 plus is normally taken as 'virtual' real time, although you obviously already know what you want. DVR Expert Australia will probably be able to advise you on the subtleties of 'GEO' systems.

Hi Ally, You don't actually say in what context 'the use of dummy cameras', but that said, I'm not aware of any court cases where their use has been brought up for legal interpretation. As dummy cameras are purely intended to act as a visual deterrent, they either work or they don't (in deterring that is ). As regards existing legislation (Data Protection Act, RIPA, Human Rights etc.) it's hard to see where any court could be asked to make a legal judgement on something as inactive as a house brick! Maybe if you could elaborate a bit, others may have more info.

No problem getting solder plugs this side of the pond Rory. I have seen problems with screw on plugs, where the braiding begins to degrade over time, and you don't get a good 'screening' contact. They may be quick and easy, but I still won't use them. Curious thought, but why do the most difficult and dangerous camera locations, only ever need a service call in high winds or pouring rain Oh yea, I remember ... english weather!!

rikky, Don't know if this will help http://www.doktorjon.co.uk/technical-lenses/lenstech11.html

Baywatch, I can't comment on the Geo / large screen issue, but certainly as regards using a Plasma screen, I wouldn't want to go there! The LCD option would be far preferable, but then if the customer has more money than sense, it may not be worth the argument; provided of course the customer is prepared to accept a written disclaimer from you about the risks of image retention. One option you could consider is projection. I've seen an impressive 'back projection' unit designed for CCTV control rooms. You'll need to have a look at Barco's website, http://www.barco.com and if I recall correctly, they have an office somewhere in Berkshire, so you could probably get some more info over the phone. (better sit down before they tell you the price!!)

Interesting that nobody mentioned solder connectors. Installers hate them, because they take slightly longer to fit (and they cost more), but for most critical applications, the failure rate is so low, it's not even worth thinking about (especially if you use adhesive lined heat shrink sleeving as a strain relief). I found the failure rate on screw ons ... frightening; and I stopped using crimps about fifteen years ago, simply because I was fed up with cleaners moving equipment on desks, and then having to go back and refit because of strained connections. If you haven't tried soldering a BNC, 25 feet up the side of a building in a high wind, you simply haven't lived (never tried it in a hurricane though ). I suppose one day I ought to get hold of a CCTV book and have a read; then at least I'll know where I've been going wrong all these years

I completely agree with kdberg about the ND filters (and they are not very expensive!) .... although their is another way of creating a variable ND filter arrangement. If you overlay two polarising filters, and rotate one over the other, the effect is from virtually clear (perhaps equivalent to NDx2), through to virtually opaque. Many decent photographic dealers (particularly long established ones) have clearance bins where they get rid of old filters and bits for next to nothing, so you can often pick up some bargains.

As dusan has pointed out, the key to the 'depth of field' issue, is going to be the angle of coverage, or more specifically, the focal length of lens used. If an ultra wide lens were used, the depth of field would probably be adequate to provide sharp-ish images over the 5 - 25 feet distance (and well beyond), even at maximum aperture. If a much narrower coverage lens is adopted (i.e. the focal length becomes longer), then the depth of field will decrease, at any relative aperture. If sufficient lighting is available at night to allow a lens iris to close down one or two 'stops', the trick would be to focus on an object around 12' away, and then the entire zone should be in focus (i.e. 1/3rd in front, and 2/3rds behind target point). Quite frankly, if you are simply looking at a front door and front yard (i.e. a non critical application), if you get the lighting sorted out, and you use a half decent 1/3" CS mount camera, you could probably get away with using a manual iris lens stopped down a couple of f stops, and the camera set to Electronic Iris function. As Rory suggested, you don't need to spend a fortune ...

The last time I saw a bad case of 'colour drift' was on a Japanese manufacturers prototype 1/3" CS camera, and that was about eight years ago. That model was AC powered!

Have you tried measuring the voltage going in, up to and beyond the point where it shuts down? It may give you a clue as to what is going on. With a brand new camera, I would have thought it's more likely to be a dry joint, or a component going open circuit after its warmed up. Either way, if you can't get it open, there's not a lot you can do with it. Power supply o.k.?

I think AVCONSULTING is probably right. Rory, why not try a test on the end corridor camera to confirm this. Turn off the fluorescents and use a temporary tungsten light source (inspection lamp or floor standing uplighter). If it is the mains frequency and their are no engineer set up switches on the camera, you only have two options; increase the light levels (sometimes works, by pushing the camera up to a higher shutter speed), or change the domes.

Spot on Thomas, couldn't agree more! Only slight problem is finding 'professionals' who know what they are doing! The difference between someone who does CCTV as their profession, and someone who is thoroughly professional in the way they do CCTV, is quite considerable. If MichaelB14 wants to have a go for himself, I'm sure he will get some solid technical support on this forum.

Hi devsac, Perhaps you could provide a bit more information? What is the application (operating theatre, endoscopy, etc. ...) ? What type of lighting are you using? What cameras have you tried so far? The problem of 'locking' the colour balance, may simply be down to the type of camera you are using. Most high end medical applications use 3-CCD chip cameras, which cost a small fortune, but you can manually set the Colour Balance, and then you don't get the colour shift problems you are describing. If you have a mixture of lighting sources (different colour temperatures), it may be worth trying a colour correction filter over the lens. Perhaps if you can provide some more background information, others will be able to come up with some suggestions.

It's amazing what you learn on this site, we'll probably be swopping recipes next I'm still not clear on this Philips issue. Is the Phillips you're talking about Rory, a completely new player, or the dutch based corporation?

Rory, Have you tried using a manual iris lens? If you get the exposure about right, and then deliberately over expose the image, see if it replicates the problem you're having at the moment?

Philips, Phillips, Fill lips, is it me or is anyone else getting confused? Thomas, I think I worked out who your Phillip was, but I still haven't got a clue what a BB gun is; bet it's not terribly legal? Rory, I'm guessing your Phillips was actually Philips; so how long have Kalatel and Ultrak been doing CCTV? I think I've now progressed from creepy onto spooky; somewhere in the 'Twilight Zone' perhaps ....

Rory, I'd keep that one a bit hush hush .... security, if you get my drift ...

After the 2000 election, I'm never, ever, ever going to the States again during an election count. When I arrived in California they were counting 'chads', and 18 days later they were still counting when I left. If I had to choose between going out at night in LA and getting mugged, or watching CNN for one minute more, I think I'd rather take my chances on the streets!

The advantages of 'line lock' with 24v AC, are not really as beneficial as they used to be. 12v DC is easier to 'back up' with an independent standby power supply, and of course, you don't have the potential for 'earth loop hum' which is always a risk on larger sites where any AC voltage is used. Provided the correct grade of power supply cable is used, a higher launch voltage can be applied with both options, to allow for voltage drop over longer cable runs. In most cases, the 12v cameras are generally smaller because their is no internal transformer in the power supply section, and for the same reason, they generate less internal heat.