Summary of important features that you MUST consider:
By all means, buy a CCD image sensor camera if you can afford, you will find it is really worth the money, you get the best quality video picture possible with high picture resolution, better vision in low illumination environment, etc. You would find CMOS image sensor cameras are very cheap, $50 or less can get you one, however you won't appreciate all your installation work when you see the picture quality especially when you can compare to a CCD camera result. Secondly, you want to get a wide view angle camera that is over 100 degree, which would cover pretty much the entire blind area in the back of your vehicle. Do not get a 30-40 degree camera if you can afford a better one, you can see more than 40 degree view through your own eyes with the help of standard vehicle rear view mirrors. Thirdly, get a good display. If your vehicle already has a navigation system, most likely your navigation system has a reserved input for rear view backup camera. If you need to buy a display, TFT LCD has best quality and is the most expensive one. However, as long as you have a CCD camera, you won't see big difference between different display technologies (CRT, standard LCD, or TFT LCD) because they are all mature technology today. Other important features that you must have include reverse/mirror image function, weather-proof, shock-proof, etc. Read on the technology explanations in the sections below for a better understanding of the image sensor, view angle, and other important factors...
Please check our "Buying from Us - Real FAQs From Buyers Like You" ebay guide for some FAQs (before and after sale) that we received from actual buyers.
Important Features and Factors
Image Sensor Technology
There are two image sensor technologies available for consumer market today. They are Charge-Coupled Device (CCD) and Complementary Metal Oxide Semiconductor (CMOS). CCD technology is the one being used in almost all digital cameras and provides the best quality picture possible. CMOS technology provides the functionality of camera-on-the-chip, it is much cheaper to produce, it has low resolution, poor picture quality in low light environment (comparing with CCD technology), and a lot of times picture and color distortions. NOTE, if a seller does not say the camera uses CCD technology, you can be assured the camera you are looking at uses CMOS technology, because people in this field know CCD technology is THE biggest selling point, and if it is a CCD camera, you would see "CCD" all over the places in the item title and description. Normally you don't find a CCD camera for less than $100 even on ebay. Recently, we noticed that there are sellers put "CCD" in the item title and description and sell the camera for about $40, these sellers know without professional technician's help, an ordinary buyer would not be able to open a camera internal board to verify the image sensor being used, nor the selling channel host such as ebay can verify that. However, you can be assured that the $40 camera does NOT use CCD image sensor, that price cannot cover the cost of a CCD image sensor itself, not even talking about the electric board, etc. SONY and SHARP are two biggest CCD image sensor manufacturers today and most CCD cameras (regardless of the manufacturer of the camera) use CCD image sensors from these two, you can check with them and find out the quantity price for say 2000 pieces.
This is closely related to the image sensor technology described above. The larger the image sensor area/size, the wider the possible/supported view angle. In today's market, the popular image sensor sensing area sizes are 1/2", 1/3", and 1/4". Normally 1/2" is not used in consumer market and has the highest price tag. What you would see most often are 1/3" and 1/4" and in most cases the 1/3" is the one that supports wider view angle. Technologically 1/4" has smaller sensor area to support wide view angle lenses, however when 1/4" image sensor is used in conjunction with special lens (described later in this section), it can support even wider view angle. Another factor determines the view angle is the lens being used on the camera and it is usually noted in "mm" (millimeters). The smaller the number you get, the wider the view angle it would give. The bigger the number you get, the further in distance (telescope effect) the camera can focus on. Popular numbers include 1.7 mm, 2.8 mm, 3.6 mm, 6 mm, 9.9 mm, 20 mm, 35 mm, etc. Normally the 1.7 mm and 2.8 mm camera would give you the widest view angle. Remember the image sensor sensing area size and the lens BOTH affect the view angle, so if you have a 2.8 mm lens with a 1/4" image sensor, it won't give you a wider result comparing with 1.7 mm lens with a 1/4" image sensor or 2.8 mm lens with a 1/3" image sensor. Another note, almost all wide view angle cameras over 100 degrees give you a bird-eye or fish-eye effect, that is perfectly normal since it is the only way a camera can give you a wide view angle. However, some latest top quality cameras (such as the ones we sell) utilize special techniques on the lens and image sensor to minimize this distortion effect.
Reverse Image / Mirror Image
Most vehicle rear view backup cameras have manufacturer pre-set left/right reverse mirror image feature, which displays a reversed camera image on the monitor to duplicate the normal view seen in a rear view mirror. This is a must have for you to see the camera view orientation correctly. If your display monitor does not have reverse mirror image feature (some vehicle-use display monitors have this feature today), make sure the vehicle rear view backup camera you choose has it. Note, some latest camera models have user-adjust left/right reverse mirror image feature, like the ones we offer, usually through a two-pin jumper connector on an extra wire. This new feature allows end user to control the view orientation and the end users can set the camera to face front and get a correct front view. If you are doing sport vehicle video shooting, this will add a great excitement. If you only use the camera for rear viewing (like 99.9% of the buyers do), just wrap the two-pin jumper connector and you do not need to use it.
This is a must for vehicle rear view backup camera, almost all models being sold have this as standard feature. However, several things keep in mind: 1) This is only for normal usage. For your vehicle to go through a high-pressure car wash, it is not considered normal usage. Also your camera will not be water-proof if the camera is submerged into water for a long period of time. There is an International Protection (IP) standard for an indication of how well the device resists entry of solid objects (first digit) and water (second digit) entry. Vehicle rear view cameras should have at least IP66 rating and preferably IP67 rating. All our cameras are at these ratings. 2) When using your camera in salt water environment such as on a boat, that is not considered normal usage either, you need to better seal your camera such as using additional silicone. There are other special situations that will reduce the weather-proof feature of your camera as well, you need to take cautions when using your camera in such environments in order to better protect your camera. NOTE, there are inside-mount rear view backup cameras on the market as well, those cameras cannot be mounted outside of your vehicle, thus those cameras are not weather-proof.
This is a must for vehicle rear view backup camera, almost all models being sold have this as standard feature. But remember this is for normal usage too, if you drop the camera from a high place to a hard surface, your will still break the camera.
Electric Voltage Rating
Most vehicle rear view backup cameras work with standard vehicle 12V power supply, some cameras (or monitor) work with 24V or even 32V power supply as well. A real vehicle rear view backup camera would be designed to operate with constantly changing voltage levels (within normal range) produced by vehicle's battery and alternator. So you need to watch out for those security/surveillance cameras that are marketed as vehicle rear view backup camera, those cameras won't work on your vehicle. However, be caution, some vehicles have a very high momentary voltage (spike) at the vehicle starting time and the overload can cause permanent damage to the camera. If that is the case for your vehicle, you will need to install an extra fuse, voltage regulator, etc. to protect your camera. Please consult professional vehicle audio/video equipment installers if needed.
Illumination Rating / Night Vision
The minimum illumination requirement rating is noted in LUX, which is a unit of illumination equal to the direct illumination on a surface that is everywhere one meter from a uniform point source of one candle intensity or equal to one lumen per square meter. 1 LUX = 1 lumen per square meter = 0.093 foot-candles. Lower LUX rating cameras work better in low light. B/W camera is more sensitive to light, so B/W camera has a nature of better night vision. Comparing between CCD image sensor cameras and CMOS image sensor cameras, you would find CCD cameras work much much better than CMOS cameras at night, the results are almost not comparable. That brings back to my statement in the opening summary, if you can afford a CCD camera, you don't even want to think of CMOS camera. Some cameras have built-in infrared (IR) LEDs that can better aid night vision, however do not count on several LEDs to make a big difference, the effect range for several IR LEDs usually is just 5-10 feet, and do not expect to see anything that is even closer to the military green color night vision goggle result you saw on TV
Some cameras have and some do not have. Audio is good to have especially when someone helps you backing up your vehicle by talking to you in the back of your vehicle. One thing to remember is that cameras have audio capability must have a microphone hole on the camera body, some low-end manufacturers do not have a good way to seal the microphone, which can reduce or even revoke the water-proof feature of your camera. Also note some display monitors (e.g. many vehicle navigation systems) do not have audio capability, so there is no need to get a rear view camera that has audio.
Wired / Wireless
We have seen more "wireless" rear view cameras recently. However, almost all wireless rear view cameras on the market today are security/surveillance cameras that are remarketed as vehicle rear view cameras. The biggest problem is that large vehicles have tons of electronics circuits that would create big interferences for wireless transmissions, so you would receive inconsistent signals, or many times no signal at all for wireless cameras. We know the convenience that a real vehicle rear view camera can bring to you, but we haven't seen one manufacturer can overcome the problem. Even for the best manufacturer who supplies all our high end high quality rear view cameras, the manufacturer does have wireless rear view cameras, but the manufacturer told us not to use on large vehicles and not to use on vehicles that require stable video signals. The wireless technology is simply not there yet for vehicle use.
Type of Cameras
There are three main types of vehicle rear view backup cameras. One is flush mount cameras (as known as keyhole cameras because many of them can be mounted directly into your vehicle's trunk key lock hole), the second one is surface mount cameras, and the third (also newest type) is license plate mount cameras (See pictures below). Flush mount cameras do not have mounting bracket, the camera body do not get exposed to the outside of your vehicle body. Surface mount cameras are easy to understand by the name and they normally come with mounting brackets. The newest license plate mount camera is easy to install on a standard U.S. license plate, but the whole camera is exposed to the outside.