What is a CPL filter for: characteristics and description

Understanding why a CPL filter is needed is quite simple. If you do not use it, the video may contain optical defects such as flare, glare, or reflections. Therefore, filters are installed on almost all recorders. The purpose and characteristics of this important device are described in the presented material.

Purpose of the filter

A CPL filter is an optical device that allows you to obtain polarized light radiation with different characteristics. Simply put, this is a filter that almost completely allows you to get rid of various types of optical defects:

• sun glare;
• exposure;
• reflection.

The filter is installed on a recorder, which continuously records while the car is moving. Thanks to this, the recording quality is significantly improved. Colors become more saturated and contrast increases, which can be seen in the comparison photo.

It is important to understand that even the highest quality filter does not provide 100% protection of recordings from optical defects. For example, the device completely blocks light reflections from a glass surface. But if the rays are reflected from the metal, partial exposure will occur.

Main characteristics

The CPL filter is a relatively simple device. Essentially, it is optical glass mounted in a frame made of durable material, such as plastic.Therefore, the filter has few characteristics - when choosing, quantitative parameters are taken into account (measured in mm):

• diameter;
• frame thickness;
• glass thickness.

How to set up a filter correctly

Setting up the filter is quite simple, but you need to know a few rules, otherwise the device will not work correctly. The main method is to turn on the DVR and rotate the optics until the image becomes of maximum quality, contrast, without glare or reflections.

Moreover, initially the car should be positioned so that it stands in bright light. There is no point in putting it in the shadow - then it will not be clear whether there will be glare on the recording or not.

If the day is cloudy, you can put a blank sheet of paper on the panel. Next, the filter carefully begins to rotate. They do this until the reflection of the paper disappears completely (cases are allowed when it remains, but only partially).

Thus, the CPL filter is an absolutely necessary part for the recorder and other recording devices. But it is not installed in all cases. The fact is that some models are already equipped with polarizing film. Its availability should be clarified in advance in the product description.