Do you ever wonder why your videos aren’t quite as ‘cinematic’ as the videos you see in the movies? Well, there are a lot of reasons for that. I can’t teach you all of the tricks. Mostly it’s because I don’t know them all. However I will try to teach you at least one here today. It has to do with ‘Neutral Density’ filters.
Neutral density filters are essentially sunglasses for your camera. It is important because photography and videography has everything to do with how much light enters the iris of the lens. Most cameras with manual controls will let you change 3 settings that control how much light is absorbed on the sensor of your lens. Or if you are a cool hipster, you only have 2 settings along with the speed rating of that vintage film stock you found at Goodwill.
The 3 settings are ‘Aperture’, ‘Shutter Speed’ and ‘ISO’. Aperture is the size of the hole that allow light to enter into the lens. Adjustable aperture lenses can change the size of hole wider or narrower. Shutter speed is how fast the shutter of the camera opens and closes with each frame you shoot. This doesn’t matter if you are shooting stills or video. Each frame still needs to be exposed to the light for the proper amount of time. If the shutter speed is too long, too much light will get it and make everything white. If it’s not opened for long enough, your frame will be too dark. Lastly, the ISO setting controls how much light sensitivity you have on the sensor (or your film stock). Modern digital cameras can have variable ISO settings whereas a film camera is controlled by the type of film you buy and load into them. The higher the ISO number, the more sensitivity you have to light and more graininess you images will possess. By varying these 3 controls, you can get just the right amount of exposure for your shot. You can get the proper exposure using various settings of your camera. But to get some more control to the style you are after, you will need to know how they work.
Sometimes you are going for that shallow depth of field look. You know, that ‘professional’, ‘cinematic’ look where the foreground is sharp and the background is blurry and vice versa. Cool kids like to refer to the effect as ‘Bokeh’. To get that, you need a combination of a wide aperture and a long focal length. I know I haven’t talk about focal length yet in the post because it doesn’t directly affect the exposure. But a combination of a long focal length (zooming in to a far object) and a wide aperture (bigger iris, smaller aperture number) will give you the most blurry backgrounds to better separate your subject.
To keep your aperture wide, you are going to constrain the other 2 settings to have the proper exposure. Because you are going after this particular effect, you’ve just lost 1 of the 3 settings you can control. If you are shooting video, you might also want to constrain the shutter speed. With too fast of a shutter speed, you will lose that cinematic motion blur when objects move across your frame. If you are trying to achieve both a blurry background and a low shutter speed, you have now lost 2 of those 3 controls. With only ISO adjustments left, you are stuck with the limits your camera’s sensor can provide which is often not enough.
Neutral density filters is here for the rescue. By having an ND filter, you can cut the amount of light that comes into your camera. A set of filters ranging from ND4 to ND64 can give you 5 stops of light control. Meaning now you can keep your aperture wide open and still only get as much light through the iris as if you had close that down 5 clicks. For example, if you want to open up your iris to f/2.8 but your proper exposure requires you to set it to f/11, a ND64 filter will let you set the aperture f/2.8 without making your shot too bright and blown out. Your awesome blurry backgrounds remain, your buttery shutter speed is kept so that car zooming by nicely blurs across your shot. You are happy.
Not all neutral density filters are the same. Just like not all camera lenses are the same. Anything you place in front of your camera is going to effect how the final image appears. High quality glass will make sure that expensive lens you have on your camera retains its sharpness and clarity. A properly shaded neutral density filter will make sure the colors of your shots are not altered into some burnt orange mess. The bottom line is, get some good quality filters.
This is especially important in drone photography and videography. Drone cameras need to be light and small. That means they usually don’t have all 3 of those controls that large cameras do. Most have fixed apertures so you can only control the shutter speed and ISO. Because the sensors are small, boosting the ISO usually starts to degrade the image quality pretty quickly. A nice set of ND filters for your drone will improve your day time videos by leaps and bounds if used properly.
Check out this video I uploaded to YouTube on what it is like to use ND filters on my DJI Phantom 4 Pro. I was sent a set of Sandmarc ND filters for the DJI Phantom 4 Pro to review and I think they work great for my drone. The images were sharp and the tints did not take away from the color balance. FYI. I was not paid to review these filters and these opinions are completely my own.
I hope this was helpful and please let me know if you have any questions about ND filters for your photography or videography projects.