Cctv Zoom Lenses And Other Options

[tubularowl]

Hi,

I have a nightvision cctv camara on the front of my house pointing out to the road. I run it through a DVR card that goes to a dedicated computer and records on motion detection. My front garden is 80ft long and I only get a veiw of any 'action' not individuals faces. I'm planning on expanding to 3 camaras soon and would like some advice. I'm moving the current camera to the rear of the property and want 2 new ones that have a fixed zoom so that I can identify individuals. It is not posible to mount a camara closer to the area to be viewed. Are these type of zooms any good or is there a better way of doing it?

Thanks for any advice you can give

[Rich]

If you are fitting cameras with a standard lens mount (C or CS mount) then you can get a variable focal type lens. That type of lens would probably be fine, but you would have to take into consideration the amount of reflected light you will have from objects at 80 feet, ie is there plenty of light available.

If you are using 2 cameras to cover the front of your property I would suggest a view probably similar to what you allready have, to give you a view of as much of the area as possible, and the second camera to give you a view of about 5 feet in height and 6 feet wide at 80 feet away, for that you would need a lens of about 50mm, if you are using a day/night camera then make sure the lens will be compatible. You will also need to think about lighting at 80 feet, possibly a IR spot lamp may work unless the area is well lit.

[tubularowl]

If you are fitting cameras with a standard lens mount (C or CS mount) then you can get a variable focal type lens. That type of lens would probably be fine, but you would have to take into consideration the amount of reflected light you will have from objects at 80 feet, ie is there plenty of light available.

If you are using 2 cameras to cover the front of your property I would suggest a view probably similar to what you allready have, to give you a view of as much of the area as possible, and the second camera to give you a view of about 5 feet in height and 6 feet wide at 80 feet away, for that you would need a lens of about 50mm, if you are using a day/night camera then make sure the lens will be compatible. You will also need to think about lighting at 80 feet, possibly a IR spot lamp may work unless the area is well lit.

Thanks for your quick response.

Some fantastic info. Not sure what C or CS mount is but I'm sure i'll find out! If I can get a camara/lens that will record an area 30ft sq at 80 ft that would be brilliant. I like the idea of keeping a camara for a general view as I have at the moment.

Available light at street level is a street lamp to the left of the property in the target zone for the close up camara. and one on the other side of the road slightly to the right of the drive. The frontage is about 55ft wide.

I like the idea of an IR spot lamp. I have never heard of them before. I currently us a 150w spot lamp located near the camara. This provides too much light at under 20ft, ok for the 80ft point but no detail. The light goes off at 11.00pm and night vision resumes.

I've not had anymore trouble since November but being a bloke I would like to make sure that if anything ever kicks off again I can nail it 1st time.

If you can provide me with any recommendations camarawise then that would be great.

PS is your profile location 'Barnsley' ?

If it is I live in Ardsley.

[Rich]

C and CS refers to the depth of the thread of the lens, most common now is CS. Basically you need to get a CS lens for a CS camera or a C lens for a C mount type camera. If you are buying them new then you just need to make sure they match.

The type of cameras I'm refering to are professional types, and it all depends on how much you are willing to spend, they would need a housing too.

You may be better off getting a varifocal lens that works with a day/night camera of the range between 6mm and 50mm. 6mm at 80 feet will give you a view of the width of about 50 feet wide but 40 feet high, probably similar to what you have.

You can get seperate IR lamps that use LED's you can also get cameras with the led's built in, you just need to find the combination for what you need, IR lamp to illumintate at 25 meters and a day night camera with about a 50mm lens.

Regarding camera reccomendations, it really depends on how much you want to spend, the budget end CCD day/night cameras will most likely do what you need.

Yes I am indeed in Barnsley, in the tarn

[tubularowl]

Thanks Rich,

you are correct that my current camara must have a 6mm lens as the veiw covers the width of the frontage. I'm clear on C and CS and will look at camaras that match the correct lens. I'm happy to spend a few quid as I am well aware of how effective a deterant it has proved. Nightvision on my current cam is pretty **** which is why i need a light on but daytime is ok. That one is going round the back anyway as there is only a smallish area to cover.

for your help

[Rich]

No problem, if you need any more help just shout.

My calculations for the 50mm Lens were based on a 1/3 inch CCD chip, that will be the chip in the camera and will be stated if you check the camera specifications that you find.

If you find anything you like the look of feel free to post links here for oppinions.

Best of luck.

Oh and if you get a seperate lens and camera, make sure the ccd chip size and lens aperture match. Options are usually, 1/4 inch, 1/3 inch, 1/2 inch. You will most likely be looking at 1/3 chip cameras though.

[Doktor Jon]

"C and CS refers to the depth of the thread of the lens, most common now is CS. Basically you need to get a CS lens for a CS camera or a C lens for a C mount type camera."

Just to clarify a slight inaccuracy, the C and CS lens mounts are actually identical in appearance, but the difference is in terms of the distance at which each lens type brings the image in to sharp focus on the imager.

A CS lens has a back focal point at 12.5mm, whilst the C mount lens is 17.526mm.

As such, a CS mount camera can accept CS mount lenses, or C mount lenses with a 5mm spacer ring screwed on the back.

C mount cameras can only accept C mount lenses.

[Rich]

Just to clarify a slight inaccuracy, the C and CS lens mounts are actually identical in appearance, but the difference is in terms of the distance at which each lens type brings the image in to sharp focus on the imager.

A CS lens has a back focal point at 12.5mm, whilst the C mount lens is 17.526mm.

As such, a CS mount camera can accept CS mount lenses, or C mount lenses with a 5mm spacer ring screwed on the back.

C mount cameras can only accept C mount lenses.

Yeah thats right, just my poor attempt of trying to simplify the difference in layterms.

[Doktor Jon]

It's late .... we're tired

[tubularowl]

I'm even more confused now than I was to start with!

I've looked at a few camaras and like the look of a camara with a seperate IR spotlamp that can record an area about 15ftx9ft @ 60ft (i'm mounting it in a slightly different place to before). I am putting the 12v and video supply cable in this week as I'm moving some network cables about. I will add a cable so I can supply the IR lamp as well. I am however still camaraless.

If I get a camara with built in IR can I still use an IR lamp or will it be too strong a light source at that distance.?

Also with a IR spotlamp, is it noticable from that distance (60ft) to passers by at night.

What size lens will I need for the size/distance req?

Thanks for any ideas.

Ray