Even if cell phone cameras keep improving and reach unimaginable levels of image quality, I’ll always carry around a larger, heavier, and more complex camera. Why is that? One word: lenses! An interchangeable lens camera opens up a vast world of photographic visions through a huge variety of optics. Choosing among the dozens and even hundreds of lenses can be confusing and intimidating, so in this beginner’s guide, I’ll explain the types of lenses available and what you should buy.