ND Filter erklärt

When it comes to accessories for camera drones, there is always talk of ND filters - the so-called neutral density filter. But what exactly does an ND filter do on a camera drone?

When we talk about an ND filter (neutral density filter), we mean a glass or plastic disk that can be screwed or inserted in front of the lens of a camera. The effect of an ND filter can be compared to sunglasses. In principle, ND filters are not used to take darker pictures. Nor are they used to protect the camera subject. ND filters reduce the amount of light that passes through the camera lens onto the camera sensor. ND filters have different markings, the factor. This indicates how permeable the filter is to light. Simply put: the higher the factor of the filter, the less light it lets through.

Basically, the following applies:

the ND4 filter only lets through 1/4 of the incident light
the ND8 filter lets through 1/8 of the incident light
the ND16 filter lets 1/16 of the incident light through
etc.

Why should I use an ND filter?

As already mentioned, the aim of using an ND filter is not to achieve a darker image. The use of ND filters is more about supporting the variable settings of a camera. As a reminder: the longer the exposure time, the more light falls on the camera's sensor. However, aperture settings are generally not possible with drone cameras. Medium-priced camera drones in particular - such as the DJI Mavic 2 Pro, DJI Mavic 2 Enterprise and DJI Mavic Cine Combo - do not allow individual aperture settings. This in turn means that the correct exposure of the subject can only be achieved through variable shutter speeds and ISO values.

At the flight altitudes of a quadrocopter, the amount of incident light or shooting light is significantly brighter than on the ground. You therefore need to adjust the ISO values and shutter speeds accordingly to avoid overexposure. However, a higher shutter speed can quickly result in a distorted image - the infamous "Jello effect". This can be remedied by using an ND filter with a corresponding factor: when using it, you can do without a higher (slower) shutter speed and at the same time avoid overexposure.

ND filters may also be necessary if a smudge or flow effect is to be achieved by using a slow shutter speed - a so-called long exposure. Possible motifs here are long exposures of highways, fireworks or waterfalls.

Our recommendation for the use of ND filters to suit the respective lighting situation

ND4 filter: Use on cloudy but sunny days.
ND8 filter: Use on slightly cloudy yet sunny days.
ND16 filter: Use on cloudy days and sunny days.
ND32 filter: Use on cloudy and very sunny days, on cloudy and very sunny days and on highly reflective surfaces such as snow or water.