With film photography still increasingly popular today among younger photographers, it can be daunting (and at times, frustrating) to shoot precious film and get properly exposed photos. This is especially the case if you have a manual camera that requires you to input the correct setting before taking a shot. Fortunately, there’s an easy cheat code that you can use to get the exposures right (more or less): the Sunny 16 Rule.

UK-based Tatiana Hopper quickly explains how it works in her video above, prompted by all the questions she has been getting about it. First, she discusses the Exposure Triangle — how ISO, aperture and shutter speed all come together to create an exposure. Then, she explains how to set each element to make sure your exposures are correct. By keeping the Sunny 16 Rule in mind, you’ll be able to quickly set your camera manually to get the exposure you need, even when you’re shooting with a digital camera.