Cameras for a parking lot

[sjmaye 0]

I work in a manufacturing plant and I need to purchase cameras for watching the parking lot day and night.

 

Our 15 year old B&W cameras have done OK, but they are tired and need updating.

 

I am looking for something like this:

 

*I would like the camera to be color, but would be OK to switch to B&W at night for additional sensitivity.

 

*We have pretty good parking lot lighting, but if I need additional lighting I will either add more lighting or infrared illuminators such as the Extreme units I have read about here.

 

*I will be mounting most of the cameras at one point and directing them to quadrants of the parking lot, so I will need to work with lenses to get the magnification right.

If anyone knows a site that gives tips on setting up camera layout on something like this I would appreciate it.

 

* I want to setup at least one camera to catch a shot of the driver of cars entering and a shot of the license plate leaving. Anything special needed here?

 

Thanks in advance for help and replies!

[rory 0]

Depending on the budget, a wide Dynamic Day Night would be what you would want for the general cameras. Something like the Panasonic WV-CP480. A wide dynamic camera helps with all the difficult lighting situations such as glare from vehicle lights.

 

It is a TRUE day night camera also, so it has higher resolution in BW mode, and true color in color mode.

 

Sanyo also has a version of this. Also if using Infrared then the camera you need will differ, as not all Day Night Cameras will recognise certain Spectral Responses (IR Types). Eg. 850nm = Red Glow, 940nm-1100nm = Invisible Glow. Sanyo and GE both have cameras that recognise the IR up to 1100nm. Im not sure on the others, they dont say. Ive used the SAnyo with 850nm and it works well, with Extreme CCTV also.

 

As for lenses, you may want to look at getting your hands on a ViewFinder. This is like a varifocal lens tool, lets you know what view you need before you install the camera. Ganz (Computar) sells these. You could stand at the camera location and then adjust it to know what exact lens you need. Id still get a varifocal lens for the job ofcourse, but this will help give you the range of lens you need. Eg. 4-9mm, 5-50mm, or 7-70mm.

 

As for capturing the driver and licence plate, this is a totally different thing.

Im doing a job like this here this or next week, they ended up just using regular vandal proof low light domes and adding alot of light, though i made sure they know it wont get licence plates.

 

First to get licence plates, you need special software that grabs the plate number from the video and converts it into text then into a database. This isnt cheap. It is also a PC card, and requires a seperate PC from the DVR. You also need to really buy a special Licence plate camera, such as the REG-L from ExtremeCCTV. There are also others, but not too many, the others are mostly still image cameras and not CCTV.

 

Alot of cameras claim they can do this and that, with extra lighting etc. but they cant Guarentee it like Extreme can, and with no extra lighting also. Extremes is not cheap though. And also take into consideration the speed of the vehicle, as that can cause the DVR or even the software to not capture the plate, which ExtremeCCTV REG cameras are designed for, such as speeds as high as 60mph. There are certain distances that you need to mount it at, from the camera to the car, height of car, height of camera, etc. Basically a regular DVR/PC DVR wont do the job also. They can claim to, even at 480pps real time, but they dont do it 100% of the time. And 100% of the time is what counts.

 

As for the driver, you can simply install either a lot of lighting pointed at the vehicles, or install Infrared with IR cameras. Either way you need alot of light to shoot inside the vehicles to get the person inside, no matter what camera you use. A wide dynamic camera would be best in this case, though once the light is behind the camera you can get away with most any color or BW camera. Day time is not such an issue, but night time is the issue.

 

Backlighting, vehicle Lights, low Light, and sunlight are all issues to consider when placing a camera for this application. Also dont forget wiring as you dont want to run the cable too close to high voltage lighting, and if it is a far distance look into amplifiers (or Active Cat5 or even fiber).

 

Rory

[sjmaye 0]

you may want to look at getting your hands on a ViewFinder

 

You are referring to the VM300? If so, no problem.

 

As far as license plates. I really don't think I need to go super expensive or hi-tech. It is by no means essential that we get a license plate 100% of the time. Just a thought that might be helpful. We are a manufacturing plant out in the country. Sure, every once in a while we have some thought that someone may be trying to break in to a car, but that has been maybe 3 or 4 times in the last 20 years.

 

I am simply taking our old cameras and time lapse VCR and bringing them a little more up to date. I built a DVR (capture card and PC) and now I am working on cameras and wiring. I know once I have this thing up and running no one will update it again for some time, so I thought I would do as good a job as possible.

 

Thanks for the reply and info, Rory!. I will look up the cameras you mentioned.

 

PS- I am trying to work out the spread of the cameras.

 

Is there a rule of thumb on just how much parking lot I should try to cover with a single camera?

 

It would seem you don't want to cover too much because you then don't get as much detail and if you have to blow up the image to look at something small it would get really blurry. Any thoughts or pointers here??

 

Any problems locating all the cameras in one spot and spreading them across the lot? Or should the cameras be as perpendicular as possible to the lot?

[rory 0]

Thats probably it, I have it in the jeep, I dont want to be a statistic on my own camera system though as its 6am ... ;-0

 

Basically anything beyond 50' you wont make out much. It also depends on the lighting and other things as to how far from the camera you will see clear.

 

You would get better coverage mounting the cameras seperate from each other.

 

Rory

[Cooperman 0]

Hi sjmaye,

 

You've had a lot of good advice from rory, so I'll just add a couple of suggestions.

 

First off, without knowing the size or shape of your parking area, I'll have to be deliberately vague re: layout. You said that general lighting is good, and can be further upgraded if necessary.

 

Where the vehicles enter the parking area, you want to make sure that they do so in a fairly narrow driveway. If at all possible, you also want them to slow up as they enter the 'recognition zone', so possibly a speed hump, possibly a turn in, either will bring the vehicle speed down to a more manageable level; in other words, basic vehicle management if practical.

 

If you increase the night time illumination just in this small area using an illuminator offset to one side this will light the occupants without major glare from the windscreen; you would ideally want to locate the camera about 75' from the recognition zone, and if you use a 1/3" camera, go for a lens around the 50mm focal length (if the ground is level, try fitting around 12 - 15' high). Now, if you use Infra Red, you are limited to a quality Day / Night 'box' camera. If you use 'White' light, you can use a decent colour camera.

 

My personal preference would be to go for a very good quality high resolution camera fitted with Electronic Iris, and use a manual iris lens, perhaps set to somewhere around f2.8 > f4. Camera fitted into a normal weatherproof housing.

 

This is 'unconventional' by most peoples standards, but the idea is that where the EI controls exposure during daylight hours, the high shutter speed (perhaps 1/50,000 in bright sunlight) will effectively freeze each image captured (30 frames / second in the States) so there is no blurring in the recording. If you use an Auto Iris lens, you cannot exploit this advantage.

In the past, this technique has worked well up to quite high vehicle speeds, but you must make sure you have enough illumination at night (remember you are only lighting a relatively small area) - you should still be achieving perhaps 1/100 > 1/200th shutter exposure if you get the lighting right.

 

For rear number plate capture, exactly the same technique, but perhaps locate the camera slightly closer, maybe around 60 feet (I don't know the size of US plates compared to UK plates, so you may need to experiment a bit.

 

When setting up cameras to cover the parking area, ideally you do not want them located in the same place; crossing over / in opposition would be preferable. Try and keep the angles narrow and view at distance, rather than wide angles close to.

 

If you roughly sketch out the area on paper (to scale), mark up possible camera locations and then cut up pieces of paper to match the lens angles, you can move them around to see how best to cover the area, with the least number of cameras.

 

The principles are exactly the same as we used to use for plate recognition with old B/W 'tubed' cameras, but there wasn't the advantage of Electronic Iris in those days!

[sjmaye 0]

Basically anything beyond 50' you wont make out much. It also depends on the lighting and other things as to how far from the camera you will see clear.Rory

 

Wow, I thought distance form the area you want to watch was simply a matter of picking the right focal length lens. If you need to watch an area further away you get a longer focal length lens and vice versa. Is the 50' limit becuase there are serious limits as the lenses available? Or what is the limiting factor to getting clarity at a distance?

 

Where the vehicles enter the parking area, you want to make sure that they do so in a fairly narrow driveway. Cooperman

 

No problem. The drive is almost single lane up to the parking area. I could increase illumination just as it opens up. We are having some paving work done this summer. I might ask them to add a speed bump at this point.

 

This is 'unconventional' by most peoples standards, but the idea is that where the EI controls exposure during daylight hours, the high shutter speed (perhaps 1/50,000 in bright sunlight) will effectively freeze each image captured (30 frames / second in the States) so there is no blurring in the recording. If you use an Auto Iris lens, you cannot exploit this advantage.Cooperman

 

I guess I don't get what you are doing with the manual iris on the lens and the eletronic iris . How are they interacting. One by day one by night?

 

I really appreciate all the info, guys. I know this is one of those things I am just going to have to try in order to gain experience. I will be runnign cable in the next couple weeks.

[rory 0]

Wow, I thought distance form the area you want to watch was simply a matter of picking the right focal length lens. If you need to watch an area further away you get a longer focal length lens and vice versa. Is the 50' limit becuase there are serious limits as the lenses available? Or what is the limiting factor to getting clarity at a distance?

 

its the distance from the cameras view.

[Cooperman 0]

The distance from camera to target issue, is relatively easy to grasp, but becomes technically more complex as conditions become more challenging.

 

Under normal daylight conditions, cameras can quite conceivably be fitted with hyper telephoto optics (1000mm +) to pick up targets hundreds if not thousands of yards (or metres) away. The problems are 1) as distance increases so too does atmospheric obscuration (e.g. mist, fog, rain, smog etc.) although the effect of this can be significantly reduced by imaging at Infra Red frequencies in Black and White. Where it can become a serious problem is in locations where for example coastal fog can drift in, or dust storms can blow up in desert regions.

 

2) As the focal length of a lens increases, in general terms, the maximum available aperture (iris) reduces, so you need more light to achieve a decent image.

 

3) As the focal length increases, the 'depth of field' decreases so it becomes more difficult to maintain focus on a target, other than in a very small identification zone.

 

4) With any lens much over 100mm, even a slight wind loading on the camera housing, can result in a noticeable (if not nauseating) level of movement in the picture.

 

5) As focal length increases, the width of coverage decreases, so you have to make sure that targets are travelling pretty much along the axis of the lens field of view.

 

Obviously at night, the longer the focal length (generally 160mm+) and therefore the smaller the maximum aperture, the greater the level of illumination needed to achieve a decent quality image.

 

The way that Electronic Iris works, is exactly the same as an aperture priority automatic photographic camera.

When you set the required aperture on the lens, the camera then automatically adjusts the shutter speed (usually between a range of 1/60 [NTSC] or 1/50 [PAL] up to perhaps 1/100,000 of a second, to ensure correct exposure. As the shutter speed increases, any target movement is then effectively 'frozen'.

 

During the day, if it's bright and sunny you can expect exposures at perhaps 1/50,000th, and at night when it's illuminated to the correct level, perhaps 1/200th of a second.

 

If you were to use an Auto Iris lens, the aperture would change automatically, but images would always be sampled at the basic rate of either 1/50th or 1/60th of a second, unless you manually selected a shutter speed, for example 1/200th second (not all cameras offer this option, and Auto Iris lenses are generally less efficient than Manual Iris in terms of optical performance, particularly with larger apertures at night).

 

I hope this all makes sense

[sjmaye 0]

Hey Cooperman,

 

That makes a lot of sense. But I am still a bit gray on one matter.

 

Your quote:

My personal preference would be to go for a very good quality high resolution camera fitted with Electronic Iris, and use a manual iris lens, perhaps set to somewhere around f2.8 > f4. Camera fitted into a normal weatherproof housing.

 

So, what is the use of the manual iris? Just setting the maximum aperture. Then you let the EI takeover from there?

[Cooperman 0]

Hi sjmaye,

 

Almost right on the EI,

 

If you set the lens to maximum aperture, it will probably over expose the imager in very bright sunlight (not such a problem here in the UK ) simply because the fastest shutter speed, just isn't fast enough.

 

You could fit a 'Neutral Density filter' which will make the EI work o.k. (by cutting down some of the light passing through the lens), but without the following advantages;

 

By closing the aperture one or two stops, it allows the camera to cope with full sun, but at night you will need to increase the light level to achieve a good quality picture (perhaps 100 - 200 lux in the target area), or use Infra Red if it's a Day / Night camera with switchable cut filter.

 

The other advantages of closing the iris a couple of stops are, you increase the depth of field, so the target stays sharper for longer, and the optical performance of the lens also increases significantly, so again sharper resolution right across the imager chip.

 

When you eventually buy a suitable camera for testing, if you can get the lens on 'sale or return' then you can try out the settings, and see how little lighting you can get away with at night.

[FredB 0]

Great info Cooperman. Learned alot.

 

Thanks,

 

Fred

[kaysadeya 0]

Same here.... Another thanks to Cooperman.

[FredB 0]

Couple of questions

 

1. If you use a housing and mount the camera in the back to shade the camera from the sun or if you have the camera facing north or south, would you still (in general, experiment needed of course) have to close the iris a little on the manual iris lens?

 

2. If you then mount the camera in a location where there is never direct sunlight (loading dock overhang, lobbies etc.) there would never really be a need for auto iris lenses?

 

3. 1/3 verses 1/2 lenses? It would make sense that 1/2 lenses would in general have a lower aperture rating then 1/3 lenses since I would asume they would let in more light. Would it then be better to use 1/2 lenses in lower light conditions.

 

4. Quote: (not all cameras offer this option, and Auto Iris lenses are generally less efficient than Manual Iris in terms of optical performance, particularly with larger apertures at night).

Do you feel in general that manual iris lenses are better designed or... then Auti Iris lenses.

 

5. How does this all effect WD cameras like the GE Ultra View etc. in terms of Manual or Auto Iris?

 

6. What other advantages are there with 1/2 lenses on 1/3 cameras, if any?

 

Agree that manual lenses look better, but never looked at it that way.

 

Great info!

 

Fred

[Cooperman 0]

Hi guys,

 

Glad you found the info useful,

As for the supplementary questions, hold on chaps we're going in .....

 

originally posted by FredB

Couple of questions

 

1. If you use a housing and mount the camera in the back to shade the camera from the sun or if you have the camera facing north or south, would you still (in general, experiment needed of course) have to close the iris a little on the manual iris lens?

 

The obvious point is it's not whether the camera is in direct sunlight or not, it's the level of light which is reflected from the target area which is relevant. It is always preferable to operate a lens as close to it's mid aperture as is practical (typically f5.6 ish) under the given lighting conditions.

 

 

2. If you then mount the camera in a location where there is never direct sunlight (loading dock overhang, lobbies etc.) there would never really be a need for auto iris lenses?

 

True. Personally, I will never use Auto Iris lenses unless I absolutely have to, and in fact, I don't recall using any indoors under controlled lighting, in the last ten years.

 

 

3. 1/3 verses 1/2 lenses? It would make sense that 1/2 lenses would in general have a lower aperture rating then 1/3 lenses since I would asume they would let in more light. Would it then be better to use 1/2 lenses in lower light conditions.

 

If you standardise on 1/3" cameras, you have the best of most worlds; generally, very good performance overall (S/N is usually lower than a 1/2" camera, but this is not normally a problem for 90% of applications), and the plus side is you have the option of using any lens from 1/3" up to 1" format.

 

In general, 1/3" lenses often have a slightly faster maximum aperture (say f1.2 instead of f 1.4 for a 1/2" equivalent), so they actually work better at max. aperture in low light situations. Now a but, and this is a big but; optically the lens performance will nearly always be better with C mount lenses, rather than CS, and where larger format lenses are used, their optical performance is far superior to their smaller format cousins.

 

 

4. Quote: (not all cameras offer this option, and Auto Iris lenses are generally less efficient than Manual Iris in terms of optical performance, particularly with larger apertures at night).

Do you feel in general that manual iris lenses are better designed or... then Auti Iris lenses.

 

The main problem with most AI lenses is that they are fitted with an internal 'spot' filter to allow the effective aperture to reduce to a minimum of f64 or f 360 depending on whether it is a DD or AI model. Whenever something is introduced into the light path, it cannot help but have a detrimental effect on the optical quality. Again larger format 'C' mount lenses are the best overall, but they cost big bucks by comparison with bog standard 1/3" Direct Drive lenses.

 

In many situations, it is not a problem to slightly increase the ambient light level, and then stick to MI Lenses with the Electronic Iris function enabled on the camera. A quick example for you; I had a demo of a manufacturers new 'high end' Wide Dynamic at the IFSEC show last week. The camera was deliberately set up looking towards a light panel, with pedestrians passing in front. The camera worked well from an engineering point of view, but the cost of the camera + AI lens was about US$ 200 more than a conventional equivalent with manual optic. Slightly increasing the foreground lighting would perhaps have cost the equivalent of US$ 100 max. and the picture quality would undoubtedly have been better overall.

 

 

5. How does this all effect WD cameras like the GE Ultra View etc. in terms of Manual or Auto Iris?

 

Many of the cameras you guys use Stateside are not readily available over here, plus of course our PAL standard cameras are noticeably different from NTSC. The short answer would be that whenever it is possible to apply relatively low tech solutions (like manipulating lighting to best effect), I would if possible rather go that route, than having to rely simply on an engineering solution, like Backlight Compensation or Wide Dynamic.

 

 

6. What other advantages are there with 1/2 lenses on 1/3 cameras, if any?

 

If you consider the vast range of lenses available from 1/3" to 1", provided the budget will stretch, you're really spoilt for choice. If you can use very good quality 1/2" or 2/3" lenses, you should see a difference!

 

 

Agree that manual lenses look better, but never looked at it that way.

[sjmaye 0]

Depending on the budget, a wide Dynamic Day Night would be what you would want for the general cameras. Something like the Panasonic WV-CP480. A wide dynamic camera helps with all the difficult lighting situations such as glare from vehicle lights.

 

It is a TRUE day night camera also, so it has higher resolution in BW mode, and true color in color mode.

 

Sanyo also has a version of this. Also if using Infrared then the camera you need will differ, as not all Day Night Cameras will recognise certain Spectral Responses (IR Types). Eg. 850nm = Red Glow, 940nm-1100nm = Invisible Glow. Sanyo and GE both have cameras that recognise the IR up to 1100nm. Im not sure on the others, they dont say. Ive used the SAnyo with 850nm and it works well, with Extreme CCTV also.Rory

 

Hey Rory,

 

Yeah, I'm back. Can you tell I am taking this project a piece at a time?

 

The DVR has been up and running well now for about a month with the 10+ yr old cameras from the previous system. The pictures are fair at best. The biggest problem is the image is too dark at night no matter what I do and the clarity of the shot leaves A LOT to be desired.

 

I want to go ahead and buy a recommended camera to test along side the ones I have.

 

This will be for a parking lot. If I can not find a camera to get a good shot with exiting lighting I will probably just add additional light in the parking lot as necessary. It would help the camera and I think the employees would like the additional light, too (security).

 

I was considering buying either the Panasonic listed above or Sanyo(do you have a model number?). My needs are (and in this order); best low light capability, clarity of picture.

 

Any other recommended cameras that fit these needs?

[sjmaye 0]

Is the Sony Ex-View CCD 500TVL any count for this application?