What is an ND filter? (Neutral density filter explained simply)
An ND filter—short for neutral density filter —is an optical tool that reduces the amount of light reaching the camera sensor. Without affecting color, it allows for longer exposure times or the use of a wide aperture in bright light. ND filters are essential for long exposures, landscape photography, and professional video productions.
Why do you need an ND filter? (Typical applications)
ND filters help you achieve creative effects and actively control lighting conditions. They are used for:
- Long exposures in daylight (e.g. smooth water, moving clouds)
- Reduction of crowds in cities (by blocking out movement)
- Cinematic videos with motion blur (shutter rule: 1/50 at 25 fps)
- Open aperture in bright light (e.g. portraits with bokeh in the midday sun)
ND filter strengths: What does ND8, ND64 or 0.9 mean?
Filter strength is specified in various systems, which can be confusing at first. Here's an overview:
| ND designation | aperture stops | Light reduction | Optical density |
|---|---|---|---|
| ND2 | 1 level | 50% | 0.3 |
| ND8 | 3 levels | 12.5% | 0.9 |
| ND64 | 6 levels | 1.5% | 1.8 |
| ND1000 | 10 levels | 0.1% | 3.0 |
Which ND filters do I need for photography?
A useful set for getting started with long exposure photography includes:
- ND8 (3 stops): Ideal for overcast skies or light sunlight
- ND64 (6 stops): For flowing water in daylight
- ND1000 (10 stops): Perfect for dramatic effects, such as smooth lake surfaces or empty squares during the day
For video recordings, an ND4 or ND8 is usually used to be able to film with an open aperture despite the sun.
Tip: Quality pays off
Look for high-quality ND filters with multi-layer nano-coating , optical glass , and precise color neutrality . Cheaper models can cause color shifts or reduce image sharpness.
In my Filterfotograf® range you will find premium ND filters in 100×100 mm format – developed for the highest demands on image quality and reliability.
Conclusion: ND filters are more than accessories – they are creative tools
Those who can control light have creative freedom. ND filters enable effects that are unattainable with a camera alone – from a velvety waterfall to a deserted city. Whether in landscape or travel photography, a good ND filter kit belongs in every camera bag.