If you want to shoot video with a shallow depth of field in bright conditions, then you will need to use ND filters. We explain our best ND filter tips, how they work and how to use them.
If you’re even remotely serious about shooting video, you should probably consider investing in some ND Filters. In this video, we discuss the function and benefits of using ND filters with our best ND filter tips.
Many stills photographers who shoot landscapes will be more than familiar with ND filters. But while they may be a good optional accessory for stills photography, ND filters are an essential tool for video photography. This is for one very simple reason, unlike in stills photography, where you have the full range of manual exposure controls, settings when filming are less flexible.
When recording videos, we’re restricted to a single shutter speed and while you can adjust the aperture, you’re unlikely to want to do that whilst recording. Also, if you want to shoot at a wide aperture to create a shallow depth of field, you’ll struggle with overexposed scenes when in bright light. Using an ND filter makes it possible to maintain your chosen aperture settings, while still reducing the amount of light passing through the lens.
Now there are two different types of ND filter, there is the circular type and the square type. Each one has its pros and cons. With the circular type, it’s important that you get the right size for the lens you’re using. Each filter is compatible with a different size of lens thread. In the video above we use a 77mm filter with a 70-200mm lens, which has a lens thread of 77mm. If you own lenses of different filter thread diameters, you’ll need a different set of filters for each one.
But square type filters are of a universal size that fit into a holder, and then you use an adapter ring to fit it to the lens that you’re using. This means you can have the same set of filters with a different adapter ring for each of your lenses. So while it’s an advantage, it’s a bulky alternative to the more compact circular filters.
ND filters come in different strengths and can cut out a number of stops of light starting at 1 and going right up to 10 stops. You can also combine filters to block out even more light if for some reason 10 stops isn’t enough. But one ND filter that’s become popular over recent years, is the variable ND filter, which is a single circular filter that can be adjusted between two N8 stops infinitely. The advantage of that is that one filter gives you 8 different stops of range, which also means that it’s possible to subtly adjust the exposure whilst filming.
Professional video cameras such as the Canon Cinema EOS cameras, the ND filter is built-in so that a range of stops can be dialled in without having to attach a filter on to front.