Along with polarizers, Neutral Density (ND) filters are pretty much the only filters most people really need these days. But what are ND filters? How do they work and why might you want to use one for your photography? Put simply, though, ND filters are sort of like sunglasses for your camera to darken down the view coming through your lens.
But how can they really be useful? After all, aren’t we typically looking for more light when we shoot and not less? Well, in this video, Mike Smith gets into the nitty-gritty of ND filters to answer that question, illustrated by images he’s shot using one.
The sunglasses reference typically means non-polarized sunglasses. Basic ones that just dim the view. That being said, there are some combined ND polarizers out there, too, which means that if you want the effect of both a polarizer and a neutral density filter, you don’t have to stack filters and risk vignetting. They come in various strengths from a third of a stop all the way up to 20 stops, and I think there are one or two more out there even stronger than that. Typically, ND filters sit in the 3-10 stop range.
For photographers, the main use for neutral density filters, as Mike points out in the video, is for landscape and cityscape photography where you have moving subjects. They allow you to capture motion blur in moving subjects like water over a longer period of time or shoot very long exposures of scenes with slowly moving subjects like clouds to record that sensation of movement in your image that you wouldn’t otherwise be able to see.
The other feature for photography, that isn’t really mentioned in the video is when working with flash outdoors. While many speedlights and strobes support High Speed Sync these days, not all camera and light combinations allow for it. ND filters let you keep your camera’s shutter speed below your flash sync speed, preventing that dreaded black bar across your shot! We’ve featured this technique before and you can read more about it here.
How often do you use ND filters for your photos?
Short-changed on the when and why. Where is the advice for using an ND filter to allow the use of a wider aperture in bright conditions when you can’t lower the ISO and/or bump up the shutter speed?
For what it is worth, I don’t think every shot of moving water needs slow shutter speeds. Freezing the movement can work for a different look.