If you want to use the cinematic shutter speed rule but it's too bright outside, what accessory must you use to properly expose your video?

If you want to use the cinematic shutter speed rule but it's too bright outside, you must use a Neutral Density (ND) filter to properly expose your video. The cinematic shutter speed rule, also known as the 180-degree rule, dictates that your shutter speed should be approximately double your frame rate to achieve natural-looking motion blur. For instance, if you are shooting at 24 frames per second (fps), your shutter speed should be around 1/48th or 1/50th of a second. This relatively slow shutter speed allows a significant amount of light to enter the camera. In bright outdoor conditions, maintaining such a slow shutter speed will lead to overexposure, where the image is too bright and lacks detail. While you could reduce the aperture (making the opening smaller) or lower the ISO (the camera's sensitivity to light), doing so might compromise your desired depth of field (how much of the image is in focus) or might not be sufficient to bring down the exposure enough, especially if your ISO is already at its base setting. The ND filter is a piece of darkened glass that attaches to the front of your camera lens. Its purpose is to uniformly reduce the intensity of light entering the camera sensor without altering the color or other characteristics of the image. By using an ND filter, you effectively dim the scene for your camera, allowing you to keep your cinematic shutter speed, maintain your desired aperture for depth of field, and achieve correct exposure even in very bright environments.