Wireless Web Camera Specifications
- Aperture Size
- Image Sensor - CCD
- Image Sensor - CMOS
- Frame Rate - FPS
- LUX
- Resolution
- Motion Detection Smart Monitoring
Aperture Size
Effects How The Camera Gathers Light - Look for the "f" number when trying to understand aperture size. For example f/6 or f/4. There is a mathematical " square inverse relationship" to determing aperture however, instead of confusing or boring you keep this in mind: The larger the "f" number the LESS light the will reach the CCD..
The "f" value is calculated by measuring the aperture size and the distance from the lense to the CCD.
So, what's good?
Look for about f/1.8, to yield crisp and clear video.
Image Sensor - CCD
CCD stands for "Charge Coupled Device" - This is the higher end, more expensive image sensor. This devices sole purpose is to capture the image that enters via the camera lense and then convert it into a stream of data. Typically the size ( diameter) of the CCD is about 1/4" to 1".
This standard specification usually provides excellent results by gathering. Keep in mind - the larger the CCD the more light the camera can gather in low light situations.
CCD sensors are excellent a creating high-quality, low-noise images.
Why is this? Very simply, CCD sensors create ZERO signal distortion when transporting electronic charges across the chip, which produces a very clear image.
One disadvantage of CCD technology is they consume lots of power - which means poor battery life.
Paying more for a camera with CCD image sensor may be unnecessary if all you need is basic home surveillance.
Image Sensor - CMOS
CMOS - CMOS stands for (complimentary metal-oxide semiconductor). This technology converts light captured by your web cam and converts it into electrons. These electrons create a data stream which is next converted into an image.
CMOS sensors are more prone to noise due to the way photons hit the transistor element rather than the photodiode - the result is less light captured by the web cam.
How important is this regarding your web cam purchase decision?
Minimal...if you need a basic wireless web cam with a reasonably decent image quality, CMOS works great.
CMOS technology has a distinct advantage over CCD - it uses MUCH less power - about 100 times less - which means great battery life.
Also, the quality of many CMOS sensors are rivaling the quality of CCD sensors meaning the difference in image quality relative to camera cost may be marinal at best - If your on a budget or just don't feel the need to spend a lot of money, opt for the camera with the CMOS sensor. .
Frame Rate
FPS ( Frame Per Second) - A live video feed is compiled of many individual snapshots taken and viewed in rapid succession. Remember the stick drawings you made on the pages of a book, which you then shuffled with your thumb simulating movement of your "little stick guy"?
Same concept, except digital
FPS on most good wireless web cameras is about 24 FPS the most your eye can detect...any higher FPS than 24 is not needed - you won't even notice it.
To look natural your wireless web cam needs a reasonable frame rate of at least 20 FPS. Below this FPS it starts to look "jerky", which is a beef with many users.
Lux Rating
How Bright? - A measure of the apparent intensity of light hitting or passing through a surface .Rule of thumb, the lower the cameras LUX rating the LESS light you need to make decent video. Lux Rating simply is a measurement of how much light an object has cast on it. It is expressed as a number, anywhere from .001 to 32,000. Dark to bright...
Of course, this is vauge at best and is much easier to understand in "real life" terms.
For example a bright sunny day with zero cloud cover at high noon would give off a Lux rating of about 32,000.
Dinner with soft lights in your dining room? About 50 Lux
The aisles at a well lit grocery store? About 400 Lux
Midnight with a few stars...about .001 lux
Much easier to understand in real terms...
Need to record in dim light or capture video in a dark room? Opt for a LUX of at least 0.05, look for a 0.03 rating for very dark (night recording).
Resolution
Describes image clarity - In other words...how sharp and clear is the picture? You will see resolution described as 640 X 480, for example.
What this means :
First number - 640 is the number of dots or "pixels" per line.
Second Number - 480 is the number of lines displayed...think horizontal lines stacked on top of each other.
So... a 1280 x 960 picture will yield a much clearer more VIVID image than a640 x 480, simply because the higher resolution image is "packed with more pixels per line..."
Smart Monitoring or Motion Detection
Records based on Time interval or movement - You can set your wireless web camera system to track at a specific time interval or whem there is motion detected in the room.
For example, your camera may only brecord an image once every 10 seconds...to save bandwidth.
However motion detection mode keepe the camera idle until something is moving within the cameras view, if the camera detects motion (someone coming in the room, the dog roaming around, even the wind blowing in knocking something over) it will immediately start to record at a chosen FPS, 20 - 30 frames per second, for example.
When the motion ceases, the camera goes back to a static image mode again.
Many cameras feature motion detection with email forwarding which will send right to your email snap shots during the time of the movement.
Very cool.