Neutral density filters are often stated to be a landscape photographer’s best friend, and for a good reason. ND filters are designed to stop light, allowing the photographer to play with the shutter speed and the exposure. There are some crazy creative possibilities when controlling the shutter speed in broad daylight.
Let’s look at a few such situations.
Wide open aperture in broad daylight
Let’s say you’re shooting in broad daylight using an 85mm f/1.8 lens. You want to use the shallow depth of field effect to blur out the background. However, with all that light going around, using the lens at its widest aperture won’t be easy. This is where an ND filter comes into the picture. You can simultaneously use an ND filter to stop the light while using a wide-open aperture.
Capturing motion blur
Capturing motion blur is another reason you want to use a neutral density filter. Let’s say that you want to capture the rolling motion of the cloud in a long exposure. It would help if you left the shutter open for a long time. Say one minute or even more. However, that can result in entirely burned-out exposure in broad daylight or even at dawn or dusk.
The solution is to use a strong ND filter. In this case, a six-stop or even a ten-stop ND filter is the solution. Let’s say the normal exposure in the scene is 1/1000 sec. With a 10-stop ND filter, you can drag the exposure to 1 second. This significant time frame will allow you to capture those rolling effects, waterfall, or stream and blur the motion.
Great for avoiding lens diffraction
We have all seen the ugly effects of lens diffraction. If you haven’t seen it, simply stop your lens to something below f/16 and see if you can notice it in your pictures. with cheaper lenses, you don’t even have to stop down to f/16. You can see the effects of lens diffraction at a higher aperture. Lens diffraction softens image quality. This is detrimental to all kinds of photography.
With an ND filter, you don’t have to stop down the lens any more than you need to, depending on your requirement for depth of field. This prevents the influx of lens diffraction from affecting the quality of your images.