Environmental camera housings

[cctvfan 0]

Looking for a good env. housing with heater/fan. Will be deploying ~10 for the project so the right choice is important. My tendecy is to use cheap brands but please stop me if this sounds a dangerous idea, and you'd rather me spend on AD, Pelco, or other brands you can recommend.

 

Some specific questions though:

 

1- Is hinged top an important feature for easy servicing or even installation of cameras?

 

2- If heater/blower electronics fails, can the circuit board be easily removed & replaced (without removing entire housing)? Some brands better than others?

 

3- Does mist build up in glass due to temperature diff (cold outside, warm inside)? I bet wipers do not help since the vapor builds up on the inside. Any cure (assuming this is a real issue).

 

Thx

[CCTVINSTALLER 0]

Although we used to use Transpac TPH1000s (nice looking housing www.transpac.com.tw), we've started to use the Ganz housing a lot easier to install and very little heater/fan circuit faults. Not sure what other brands are good, depends where you are, make sure they're IP rated though.

 

3- Does mist build up in glass due to temperature diff (cold outside, warm inside)? I bet wipers do not help since the vapor builds up on the inside. Any cure (assuming this is a real issue).

 

Any good quality housing should do the trick, make sure the camera is as close to the glass as possible, it'll prevent reflection. Bit dazzled with this one, what do you mean by wipers ?

[cctvfan 0]

Thanks. To be honest I haven't seen one with wipers either, since none of the three models found at this link has photos.

 

http://www.spytown.com/search--by-part-number-vicon2--camera-housings--indoor---outdoor-with-wiper.html

 

But I picture them to be like winshield wipers on cars, i.e. wiping the outside but not the inside of the glass. When I wake up in the morning during winter I always had to wipe away water vapor built up on the inside of our windows. That's why I asked that question, assuming the same will happen to housings, since the camera is "living" in a comfortably heated room like myself

[AVCONSULTING 0]

I'd go with Pelco. They have the best housings and you can order them with a demister option which is different than a heater or wiper. Quality stuff. If you just want a low cost housing with heater and blower then the Vitek is ok. Here are a couple of links.

 

ftp://www.pelco.com/SelectionGuides/21030.pdf

 

http://www.vitekcctv.com/Sections.asp?SectionID=1009#20

[baywatch 1]

We have replaced a few that had wipers & the customers have never used them.

I think the only need for washers & wipers are in very harsh environments & maybe where there is a lot of traffic fumes e.g. town centre systems.

[Cooperman 0]

When it comes to choosing weatherproof camera housings, the subject could probably fill a book on its own.

 

Assuming that the camera is fitted with a fixed (small) lens, then a hinged housing is an advantage for the installation / service engineer, as there is one less piece of dropable stuff to worry about when you're up a ladder!

Mind you, if you've never had a hinged housing fall back on your fingers whilst you're twenty feet up a ladder, you simply haven't lived!

 

The main longterm problem with housings (apart from heater failure which is expected), is that various models can leak through the seals over a period of time. Top cover housings generally are the most water resistant, but there are one or two models I've seen in the past where the neoprene contracts with age, and you end up with the lens paddling in a shallow heated jacuzzi!!

 

The problem of condensation on the inside of the glass is simply down to two factors; the temperature gradient between the air either side of the glass, and the moisture content of the air inside the housing.

 

The larger the housing, the more damp air there will be inside. If the housing is small and well sealed you can pack some fresh silica gel in to absorb most of the moisture. Small 'comfortable' housings are not recommended in hot climates - you just end up cooking the camera!

 

Apart from using a thermostatically controlled heating device to clear condensation, you can also use a very small fan directed onto the glass. Condensation will not form in a draught!

 

It's actually quite rare to need an external screen wiper (and wash bottle) for a fixed camera. Generally speaking, the more horizontal the camera, the greater the amount of muck that will stick to the glass, so the more often it needs the loving attention of a friendly window cleaner.

 

Just a thought but I'm not sure what this has to do with 'General Digital'?

[rory 0]

I have used Kalatel Housings on the ocean side, and through a couple Hurricanes, and they last. I also have them in warehouses, beach side, etc. They withstand dust perfectly, never used their heater versions though, for obvious reasons.

 

But this is on the US side of the world, if in the UK, which I think you are, then just go with Pelco.

[baywatch 1]

We can supply good external housings with hinged lid & IP56 rated. They can have either 12/24 volt heaters or 240 volt heaters but don't have a fan.

We have used them for many years, we are right on the Atlantic coast and anyone who knows our part of the world (Swansea) knows how much rain we get.

If you want details & prices let me know, their not expensive.

[cctvfan 0]

Thanks all for the useful tips.

 

A follow-up question: assuming the cams support ELC / CCD iris (FYI, Sony SSCM183 B/W). For the outdoor scenarios we've been discussing, which of these lens choices would you experts prefer:

 

a. Manual iris lens, with ELC/CCD iris on camera enabled.

b. DC Auto-iris lens, disabling ELC on camera.

 

My favorite is 'a', but I want to hear from experts. I'm concerned in 'b' I will need to adjust the DC level after installation (Q: Is it real a challenge to locate the DC level dial on the back of a camera inside the housing, while I'm clinging to a ladder, and it's getting dark? Or is it not that bad?).

 

I know some may suggest, with proper site surveys done at day & night, the DC level should not need any more adjustment once the cam is installed. But we never know... so I'd still like to hear your vote on a or b.

[Cooperman 0]

cctvfan,

 

Possibly two seperate issues here. Firstly without knowing what the cameras are looking at, and what the available lighting is going to be, I would have suggested that Direct Drive or Auto Iris would be a safer bet.

 

That said, my personal preference would be to use a manual iris lens with Electronic Iris (CCD Iris) function wherever practical / possible (particularly for indoor applications). Their are quite a few reasons for that, but you do need to be rather confident with camera / lens set ups, to get away with it. If in doubt stick to 'auto iris' lenses (I would imagine the majority would go with this latter suggestion).

 

Secondly, setting up exposure control on a lens, is not really a problem. Dark on a test bench, is pretty much the same as dark up a ladder. As long as the threshold for iris control is set correctly on a bench, and then tested out of a window from sky to almost dark conditions, it should work anywhere.

 

If you're really confident, you should be able to set the lens focus as well!

A little tip for you (just don't tell anyone - it's a trade secret!) - if you want to set the lens focus on a camera which has yet to be installed into a housing which is already in place, simply wind a rubber band once around the lens body and focus ring, after it has been correctly adjusted; then the ring won't move. If you need to readjust at a later date, it's much easier to roll a band off the focus ring with your finger, then try and pick off a tape, particularly when you're 25 feet up a ladder in a force eight gale!

 

If you use tape, it tends to get very sticky particularly if you need to readjust the lens some time later.

[AVCONSULTING 0]

Almost always use an auto iris lens outdoors. First they aren't much more than manual iris lenses and second you will get maximum opening at night when you need the most sensitivity and it will close down during sunny days so the camera won't get overloaded. Auto iris lenses come with tiny lock down screws on the focus ring and also on the zoom ring if using a varifocal. One thing to remember is to focus your camera at night or by using neutral density filters so that you fool the lens into opening all the way. Otherwise you will have problems with blurry focus at night.

[cctvfan 0]

You two have just converted me.

 

I must admit I love using auto-Iris too, at least for the past (i.e. indoor) projects. As mentioned, this upcoming one, being the first major outdoor for me, makes me nervous because of the fear of having to climb back up the ladder again to re-adjust the DC level.

 

But as Cooperman said, if the pre-install work are done properly on the bench, that shoud not happen. OK I'll make sure I do the bench pre-tune deligently.

 

BTW Rory, I'm not in the UK, but in the freezing cold part of Canada.

[rory 0]

 

i watch your TV all the time, our local cable company is owned by Canadians and they play canadian TV on a few channels, and canadian commericals in between MSNBC news ...!