To PTZ or Not to PTZ

[wifi la]

I am new to this forum but wrote this up the other day and thought I would get some feedback from the experienced Vets in the forum. Have a look and let me know your thoughts. I am not sure teh images will come through here so to see the figures click here.


To PTZ or Not to PTZ: PTZ IP Cameras vs. Multi-Megapixel

I have been speaking to many many clients lately about IP video surveillance and each time we go through the pros and cons of using traditional Pan Tilt Zoom (PTZ) cameras vs. the latest multi-megapixel IP cameras and in most cases we end up deciding that the multi-megapixel cameras are the way to go. So I have decided to share these ideas to hopefully help others in accessing their own IP security needs, and the solutions to these needs.

So PTZ. What is it? PTZ or pan tilt zoom cameras have been around for years in the analog world of CCTV and have made the obvious transition to IP Video security as well. These cameras are normally enclosed in a dome and have a VGA quality sensor that sits on a multi-axis thimble so that the user/operator can move the camera up, down, side to side and zoom in on a subject to get a closer look at what is happening in a specific location. That should be pretty self explanatory but if you would like to see a PTZ camera I have included a pic for you.

As in other parts of life, there are always advancements that are not necessarily meant to contend with previous methods of doing something but after they are developed they do, and in my opinion multi-megapixel IP cameras are one of these advancements. Multi-megapixel IP video cameras allow you to see double, triple, even quadruple the amount of pixels as a standard "high-resolution" VGA camera. What this means in plain English is that you can see more of a particular view and in greater detail. If that still doesn't make sense, read on as there is a good picture below.

OK, “so what,” right? That is great you say, but what does that have to do with contending with traditional PTZ cameras? Well here is how I see it. PTZ cameras are used because an operator wants to see activity in different locations around his or her property. Well, a standard high-resolution VGA camera has a limited 640x480 field of view so it needs to be moved around to see the "BIGGER PICTURE". Ok, well what happens when you move the camera from area A to see what is happening in area B? Area A is now vulnerable. So why not use 2 fixed cameras one focused on Area A and one on Area B? Well this is a great idea but quickly becomes expensive since you then need to monitor two cameras, you have to buy an extra camera license and of course you need to buy another camera!

So a good solution is to get one camera that has enough resolution or sees a big enough picture to monitor both area A, area B and everything in between all at the same time. This is precisely what multi-megapixel cameras allow you to do. IQeye has a series of cameras that reach up to 5 megapixels, which translates into 2560 x 1920 pixels. That is 16 times the resolution of a high-resolution VGA camera which means the field of view is 16 times as large and therefore the operator can view the "BIGGER PICTURE" without leaving certain parts of the property vulnerable to attack, theft, etc... The nice thing about having all those pixels is that you can then digitally zoom in after the fact and get a closer look without the image becoming overly "blocky" or pixilated. Milestone Systems Xprotect and other NVR packages have this feature already built in.

As promised, here is a picture to try and explain all this. I'm a visual person too so here is an image I’ve made to try and explain this a little more clearly...



I took a picture of a standard University courtyard, that I found on Google Images, with the proper aspect ratio and scaled it down properly so that I could easily demonstrate my point. The green border represents a 5 Megapixel image (2560x1920) and the red rectangles represent standard high-resolution VGA cameras. You can see that exactly 16 red boxes fit inside the one green one, which means that the single 5MP IP surveillance camera can take the place of 16 standard cameras or a PTZ that is constantly patrolling but without missing a thing! In this day of University tragedies can you imagine if a crucial piece of evidence is missed because the crime happened in area A on the left but the camera operator was focused on area B to the right? I say why not see it all?

Ronen Isaac
VP of WLANmall.com and Continental Computers
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Milestone Systems Software | MegaPixel IP Cameras

[spymasterflash]

[wifi la]

Thank you for your feedback. I understand your argument but I am not sure the piece I wrote is misleading. It is an opinion. 2560 / 640 is 4 but 1920 / 480 is also 4 and 4 x 4 is 16. So with a wide angle lens and that resolution you can see significantly more area that with a standard VGA camera without the fisheye effect. Also the question is what if you do not have a guard on duty when the midnight creepers come to zoom in on them? What if you zoom in on the diversion while the real crime happens else where just outside of your field of view?

Your argument about light sensitivity is accurate. However with newer technology these multi-megapixel cameras can achieve .05 lux sensitivity in color mode. Agreed, this is not as good as a PTZ that can switch to B/W mode and achieve much lower light sensitivity but it is by no means poor.

In my eyes both Multi-Megapixel and PTZ cameras are fantastic technologies and each has their place in the IP camera market space. Both cameras have their strength and their weaknesses and it is up to the user to figure out their priorities and use the product that suits them.

The point of this little opinion piece was not to tell people to do away with PTZ cameras (because I in no way believe that you should) but simply to show people a different take on using Megapixel and Multi-Megapixel cameras.
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Milestone Systems Software | MegaPixel IP Cameras

[Roger]

I was debating the same probelm before I decided to buy the Panasonic ns202A.
I actually was looking and debating to buy the arecontvision system with 4 cameras. I was then looking at all there pictures they had online for the prospective buyer and started to notice something. The zoom was never as good as a real 10plus mechanical zoom. The nightvision was not as clear and sharp as the one from Sony or JVC in infrared. But so far I am still amazed with the very little light from my carport the Panasonic makes it a day picture. I have not tried yet how the camera is with infrared only since it does not remove the filter but I know already, pointing a remote at the camera the light from the remote looks just as on the Sony sncr25. I got the Sony for somebody who needs to watch his 1000Gallon GasTank.
At the time the ns202a had the best picture and it is still amazing but then the camera has only SD card (2GB max) you can use internally,(no SDHC) for recording. Sony uses CS cards and has a build in 8gb card. I guess there will be always something missing on any camera.
Back to the megapixel camera, not enough megapixel yet, meaning: not enough zoom, not enough nightvision. The day you have a digital zoom of a 22X plus mechanical camera,I am ready to buy one. The megapixel would have to go up to 16 or 20megapixels before they would ketch up, plus 25 frames (pictures) per second ????? Now we get something.
I know, dream on.
Money is no object brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr (I just can't find the change in my pocket right now, my wife took it out while doing laundry