High resolution IP cameras provide mega-pixel resolution not available with analog cameras. This high resolution allows you to zoom in on portions of the video and still have enough resolution to identify a person’s face or license plate number.  You can even zoom in on the stored video, providing a distinct advantage over manual PTZ cameras. Cameras are available with 5 or more mega-pixels of resolution.
 
But are all high resolution cameras equal?  It turns out there are a number of cameras that say they are high resolution, but don’t actually provide the expected resolution at the computer display. Here are some of the things to be aware of when looking for a high resolution camera.
 
Take a look at the following picture. If you have a standard type IP camera, you can view the 320 x 240 or the NTSC/PAL image.  As you increase the number of pixels you are able to see a larger picture at the same resolution and then zoom in on a portion of it. 
 

If you want to be able to view high resolution video that you can zoom, pan and tilt, you need a camera that not only includes the mega-pixel sensor, but also a good mega-pixel lens and the appropriate processing power to provide the high resolution image to the computer display and storage.  You also need software that handles the higher resolution video.
 
Sensor

High resolution cameras start with a high resolution sensor.  The cameras come with ½ inch and 1/3 inch sensors. For example 2 mega-pixel sensors have a resolution of 1600 x 1200 pixels, and a 5 mega-pixel sensor provides a resolution of 2592 x 1944 pixels. CCD (charge coupled device) and CMOS (complementary metal oxide semiconductor) image sensors are two different technologies for capturing images digitally. Each has unique strengths and weaknesses giving advantages in different applications. ½ inch CMOS sensors are used in many high resolution cameras because they provide better low light capability, have good dynamic range and better signal to noise ratios than CCD sensors.
 
 
Lens
 
Just like in standard photography, the lens can make a big difference to the quality of the final image.  Mega-pixel lenses are used to get the clearest image.  If you use a lower quality lens you will get an image that’s not as clean and crisp as one that uses the better lens. 
 
Computar, Fujinon and Kowa make a number of good mega-pixel lenses (sometimes referred to as machine vision lenses).  There are not too many lenses to pick from so sometimes you may have to compromise when you need a specific type of lens. In all cases it’s best to look for the very best lens you can find to get the best video image.
 
Image Processor
 
The cameras image processor needs to be able to process the images at high speed, compress the images without data loss and send the complete image (1600 x 1200 pixels) to the computer. If the camera processor is too slow you may only get a few frames/second. For example you may see less than 1 fps on some high resolution cameras, while some provide up to 30fps.

IP Software or NVR Software
 
There are a lot of companies that provide software that runs on your PC and provides video storage, viewing and retrieval. I previously wrote an article describing some of the things to be aware of when selecting this type of software.  One of those things is the ability to process the larger images. The software must be able to accept the larger images, process them in a reasonable amount of time, reliably retrieve and view the video.  The best software allows you to easily zoom in and pan and tilt the stored video.  Software products from ONSSI and Milestone successfully handle the high resolution video. 
 
Axis and IQinvision recommend the ONSSI product because of many enhanced features, great reliability and excellent support. They have a number of products that provide all the capability you need and more importantly operate without crashing. No one wants software that crashes, especially surveillance software.
 
Camera Examples
 
There are a number of cameras that have Mega-pixel lens. Some cameras do not provide all the functions and are less expensive, but they still may fit your application. Let’s look at some of the available cameras and see what they actually provide.
 
The Axis207MW provides a very nice image.  It includes a 1.3 mega-pixel CMOS sensor (1280 x 1024), and costs about $400. Other 1.3 mega-pixel cameras cost a lot more.  Why is this so?  Well it’s because it comes with an inexpensive 3.6mm lens that can’t be changed.  The image is better than the standard resolution 640 x 480 resolution cameras, but certainly not the same as a camera that uses a more expensive lens.  It also supports a maximum of 12fps and a minimum light sensitivity of only about 2 lux.  The camera is great for some indoor applications, but doesn’t provide all the features of a full function mega-pixel camera.
 
The Panasonic WV-NP1004 has a mega-pixel sensor (1280 x 960), but the processor only provides a resolution of 640 x 480 to the computer display.  This means you can digitally zoom in on the image (in real time only), and see more detail then if you digitally zoomed in on a camera with 640 x 480 image sensor resolution.  The Axis 212PTZ is similar to the Panasonic camera. It has a higher resolution, 3 mega-pixel sensor, but only 640 x 480 resolution is available at the computer display. That’s why they call it a digital PTZ camera. The high resolution sensor allows you to digitally zoom in and move around the image in real time, but since the high resolution is not provided to the computer, you can’t zoom in on the image after it has been stored.  
 
The Axis 223M and the IQinvisionIQ752 are examples of high resolution day/night cameras with all the components necessary to take full advantage of the high resolution.  They include the 2.0 mega-pixel sensors, a selection of mega-pixel lenses and good high speed processors.  The Axis223M supports up to 9fps while the IQ752 supports up to 20fps so is much faster.  Since all the pixels are stored at the computer you can digitally zoom and move around the stored video.  These cameras allow you to take advantage of all features available from a fully operational high resolution camera.
 
Mega-pixel cameras are also provided by Mobotix and Gantz (Arecont).  The Mobotix cameras have a number of unique features such as integrated outdoor housing and dual high resolution (day) and standard resolution (night) capability. Mobotix provides a number of cameras with fixed (non-changeable lenses, limiting their use in some applications.  The Gantz cameras are similar to the IQinvision family of cameras, but do not have as many features and provide less low light sensitivity.
 
So what’s better?
 
It just depends on your application.  If you are primarily viewing the video in real-time, you can use a camera like the Panasonic WV-NP1004 or the less expensive Axis212PTZ.  If you need to store all the high resolution video and then be able to zoom, pan and tilt on the stored video, then the Axis223M or the IQ702 will be better.

There are some trade-offs to consider. Mega-pixel cameras generate a lot of data per frame. For example, a 2 mega-pixel camera uses about 160 Kbytes/frame while a standard 700 x 480 resolution camera uses only about 30Kbytes/frame. By using motion detection and reducing the frame rate you can control the amount of storage required.  The IQeye line of cameras also includes adjustable aspect ratios, so you can view only the area of interest.  For example, if you are looking at a roadway you can cut out the area that’s showing the sky thus reducing the data size of the frame.
 
Need help selecting the right camera?  Just contact us at 800-431-1658 or 914-944-3425 or fill out the contact form.