Reverse back up rear view parking camera angle decription

Usually , people always need 170 degree angle rear view or front view cameras.But Some just need 120degree camera. How could that be ?

Please come to check two image first :

In fact , 170 degree is the across angle, then the horizonal angle should be 120 degree.
Maybe you can say lens angle is 120 degree as well.

                                                                                    If 120 degree is the across angle,the horizonal angle should be 90 degree.

As i've mentioned , 170 degree angle camera have wider visual field than 120 degree angle camera.
As you can view more area ,so the image will have little sphere shape .


Back up camera can connect with DVD/ CAR AUDIO/GPS/MONITOR (3.5 INCH/7INCH/9 INCH) etc.

Also parking sensor can match using with cameras as you like .