Fancy high tech digital exterior view mirrors on your new Lexus? “That will be GBP1,600 extra sir.”

Lexus has launched the electronic rear view system, initially on the top ES 300h Takumi sedan model.

As usual, Digital Side-view Monitor, as it is officially called, was launched initially in Japan, in 2018, to work out any bugs close to home, with Lexus claiming a world first for a high volume production car – Audi also offers the system on some models.

The system replaces conventional door mirrors with compact, external, high resolution cameras linked to in car monitors which provide an enhanced view of the area behind and immediately alongside the vehicle in all driving conditions, reducing or eliminating the driver’s blind spots and adapting automatically to give an extended view when the car is turning or reversing.

If they work as well as the dual optical/digital rear view mirror in the RAV4, which gives a much clearer, wider view in digital, the extra cost should be well worthwhile.

Lexus reckons the ergonomic design of the system allows the driver to check the view around the car with less left-right head movement, in line with the aim of reducing the driver’s workload.

The two five inch colour monitors are positioned at the base of the front pillars, closely aligned to the door mirror height, so they fall within the driver’s intuitive line of sight and he or she doesn’t have to significantly change natural mirror checking action.

The cameras are housed in slim, aerodynamic casings and, smaller than door mirrors, reduce wind noise and intrude less in the driver’s forward diagonal view.

The units have heaters to avoid freezing or misting and are located so they are not vulnerable to being obscured by raindrops or snow. If necessary, the driver can activate the demister independently.

The system has a luminescence sensor which automatically reduces glare from the headlights of following vehicles at night, giving the driver a much clearer rearward view.

Automatic extended view

When the driver uses the turn indicators or selects reverse gear, the monitors automatically present an extended view of the area alongside and behind the car, eliminating the blind spot and helping safer manoeuvres. An icon in the corner of the screen alerts the driver to the change in aspect.

When the turn, lane change or parking action is completed, the system automatically returns to its standard setting. The driver can also switch to extended view manually, or turn the function off.

The system can be adjusted using controls on the driver’s door panel, as with conventional door mirrors. A menu function gives access to system settings, including brightness and – a feature claimed unique to Lexus – automatic retraction of the camera units when the car is parked. The system also incorporates a blind spot monitor.

Automatic reference lines

The digital ‘mirror’ system also helps the driver position the car when parking or driving, automatically adding reference guidelines to the images.

When parking, the lines indicate 20cm and 50cm distances from the rear bumper, and 50cm along each side of the car. These are shown on the live image and also in an icon on the display depicting the car’s position viewed from above.

When highway driving, the driver is helped to judge safe distances from other traffic with reference lines indicating 5m, 10m and 15m on the road ahead when driving at speeds up to 44mph (70km/h). At higher speeds the distances are 5m, 10m, 15m and 30m.