This design of reversing camera has been around for many years. They are the most popular design for larger vehicles such as motorhomes, caravans and white vans. Our supplier for these cameras use top quality moulds that use rubber seals rather than sealant you find in cheaper cameras. They are tested to IP68 and in our experience vary rarely have issues with water getting in. They use a 1/3" Sony 700 TVL CCD sensor which gives an excellent picture day and night. We use a stainless steel bracket to avoid corrosion of the bracket which is common with mild steel ones.
The one photograph shows the field of view obtained by this camera. At a typical mounting height it will cover the full width and more of the vehicle. We find manufacturers quoted camera angles are always inaccurate which is why we show the camera in a real situation.