Neutral density filters (ND filters) are crucial tools, reducing the amount of light entering the lens. This allows you to achieve longer exposures even in bright conditions, creating stunning effects with moving elements like water and clouds.
Coming to you from Jason Row Photography, this informative video explains the essentials of ND filters. The primary use of ND filters is to reduce shutter speed for capturing ethereal landscapes. The filters are graded by stops of light reduction: a 0.3 ND filter reduces light by one stop, a 0.6 by two stops, and so on. For bright sunny days, you may need ND filters with higher stop reductions, such as ND8 or ND64, to avoid diffraction and maintain image quality.
Quality ND filters are essential. Cheaper filters can introduce color casts, complicating your post-processing work. Investing in high-quality ND filters ensures better results. Variable ND filters, which allow you to adjust the density by rotating the filter, are popular among videographers. They help maintain the 180-degree rule, which dictates that the shutter speed should be double the frame rate. This balance is hard to achieve in bright light without ND filters, even at small apertures like f/22.
The video also touches on different types of ND filters. Screw-in filters attach directly to the lens's filter thread, but if you have multiple lenses with different filter sizes, you will need several filters. Square filter systems, such as those by Lee Filters, offer a versatile solution. You attach an adapter to each lens, allowing you to use the same set of filters across all your lenses. Recently, magnetic filters like the Kase Wolverine series have gained popularity. These filters combine the convenience of screw-in filters with the flexibility of square filters, offering a quick and easy way to attach and detach filters.
A good tripod is essential when doing long exposures, as any movement can ruin the shot, especially with shutter speeds exceeding one second. The comparison between images taken with different ND filters highlights the dramatic changes in the look of the water, emphasizing the creative potential of these tools.
Check out the video above for the full rundown from Row.