Should the rear camera be inside or outside the car?

When installing a rear camera for a mirror-type drive recorder, is it better to install it inside or outside the car? We are often asked this question.

First of all, the basic premise is that installation inside a car is easy even for beginners, while installation outside a car is often labor intensive and difficult.
If a beginner wants to install by himself/herself, he/she should almost always choose installation inside the car. If you often maintain your own car or ask an installation company to do the installation for you, then you should do the installation that is appropriate for your car model.

On top of that, which one is better suited for your car depends on the type of car. The advantages and disadvantages of each are summarized below.

Inside the car

Advantages: Easy to install, good visibility in the rain with rear wiper
Disadvantages: image is affected by the density and color of the rear glass smoke, not suitable for strongly lying rear glass, difficult to see in the rain without wipers

Outside the car

Advantage: Can be installed independent of the color and shape of the rear glass
Disadvantages: Difficult to install, white splash by headlights of rear vehicles if positioned low, sometimes difficult to see in the rain, lenses damaged when put in car wash

Each of these is explained below. The following sections also explain how to conduct installation tests inside and outside the car at the end of this section.

Car models suitable for installation inside a car

For standing rear-glass car models such as the one below, we recommend installation inside the car. Relatively strong smoke is often not a problem.

However, in the event of rain, water droplets on the rear windshield will be a nuisance, so the windshield wipers should be placed where they can reach. In this way, a very clear and bright rearward view can be obtained even in the rain.
If you do not have a rear wiper, try applying a glass coating to make it as water repellent as possible.

If the smoked film appears dark and dark, it can be improved by hollowing out the film only around the camera.

For in-car installation, be sure to attach the camera directly to the rear glass with a special bracket. However, in this case, the distance between the rear camera and the glass will be larger, so the image quality will not be as good as in the case of a car with a strongly lying rear glass as described below.

In addition, dirt on the rear glass directly leads to deterioration of image quality. If the light appears to be diffused, especially at night, the rear glass is dirty. Wipe both the front and back of the glass frequently, even if it is only around the periphery of the camera, to clean it. The camera lens should also be kept clean by wiping it with the cloth provided with the product.

Car models suitable for installation outside the car

For car models with a strongly lying rear glass as shown in the photo below, installation outside the car is recommended.

When installed inside a car with such a strongly lying rear glass, the rear camera image will also show the interior because of the slight distance from the rear glass.

This makes it difficult for the rear camera sensor to determine whether the brightness should be adjusted to the bright exterior or the dark interior of the car. As a result, the brightness of the image tends to change frequently.

Also, because of the angle, the smoked color of the rear glass appears darker relative to the camera's view. As a result, the overall image tends to be darker.

However, since this depends on personal tolerance, we recommend that you try a simple installation inside the car and check how it looks with your own eyes.
There are many people who have no problem installing the system inside the car even for these types of vehicles.

The "Mirror Cam" series comes with brackets for both inside and outside the car, so you can install it inside the car and then re-install it outside the car without any problem.

Installation position outside the car

When installed outside the vehicle, it is often placed above the license plate number, but it is recommended to place it as high as possible.

The reason is that if the camera is installed near the license plate number, it will be directly exposed to the headlights of the vehicle behind it at night, which may result in whiteout of the video image.

However, whether this point is acceptable or not also varies greatly from person to person. There are many people who consider it as such and are not particularly concerned about it. In fact, it can be said to be much better than this, since the headlights are so bright that it is impossible to look directly into them at night with ordinary mirrors.

As you can see in the photo above, even when exposed to direct headlight illumination, the license plate number can be properly photographed by software processing. With the naked eye, nothing can be seen under such conditions. It may seem dazzling, but in reality it is only the amount of light from the LCD backlight, just like looking at a smartphone in the dark.

In order to prevent whiteout, it is best to install the unit outside the car at a position as high as possible, especially under the rear spoiler. In this case, however, please note that if there is a high-mounted stop lamp in the spoiler section, the light from the stop lamp may be reflected when braking.

Another option is to flip the rear camera upside down and install it on the roof top (note that MirrorCam Pro MRC-PRO1/G does not support upside-down installation). In this case, it is difficult to see directly under the car, making it difficult to use the camera as a rear-view camera when parking.

Glass coding agent, car wash

If the camera is installed outside the vehicle, applying a glass coating to the lens of the camera can be expected to repel water when it rains. However, the coating often peels off even when the car is washed or touched with a finger, so it is necessary to reapply the coating frequently.
In addition, the aforementioned areas above the license plate number and below the rear spoiler are less likely to be directly exposed to rain and provide stable visibility even in the rain.

Please avoid using a car wash machine if at all possible when installing outside the car. If you must use a car wash, please protect the rear camera, especially the lens, with duct tape. The rear camera of the Mirror Cam is waterproof, but if the car wash brush hits the camera too hard, there is a risk of flooding or scratches on the camera body or lens.

Fine scratches from a car wash brush will frost the lens, causing diffuse reflection and diffusion of light, especially at night. Fine scratches on the lens are difficult to see with the naked eye, but if you touch the lens with your finger and it feels gritty instead of smooth, there is a high probability that the lens has fine scratches. However, even if this is the case, it may be reduced by applying the aforementioned glass coding agent.

Tip: In the case of convertible cars

In the case of convertible cars, the basic installation is outside the car due to its structure.
However, in order to reduce the whiteout mentioned above, some people install it above the seats or on the roll bar inside the car. In this case, as mentioned above, we recommend that they be installed as close to the rear glass as possible.
Depending on the model of car, it may also be possible to install the screen outside the car in the rear trunk area, upside down (except in the case of the Mirror Cam Pro).

As for whether the screen is visible when the car is open, most people say that if the angle of the mirror is adjusted correctly, the screen can be seen well enough.
However, depending on the time of day (position of the sun), it may be difficult to see the screen.

It is also possible to install the screen on the dashboard as a DIY project. If the screen is installed on the dashboard, you can check the rearward view of the mirror cam at the same time while keeping the existing mirror in place.

To test the installation

The basic concept has been explained in the previous sections, but if it is difficult to determine the best solution, we recommend testing the system both inside and outside the car.

Testing the installation in the car is very easy, as it is simply affixed to the rear glass. No interior embedding of cables is required during testing.

Although it may seem difficult to install outside of the car, it is not so difficult if it is considered as a test. For example, if you have a hatchback car, you can pass the cable directly under the hatchback as shown below. The hatchback door usually has a gasket, so if you open and close the hatchback door slowly and carefully, the cable will not be disconnected. In fact, we also do this kind of simple wiring when testing. (However, there is a risk of disconnection, so please open and close the hatchback slowly and carefully.)

When removing the rear camera bracket that has been attached for the test, use a peel-off tool to slowly and carefully peel off the double-sided tape from the edge. If you remove the bracket by hand, the bracket will be warped and cannot be reused.