What Is a Camera Lens? A lens is a tool used to bring light to a fixed focal point. In a film camera, the lens sends the light to the film strip, while in a digital camera (like DSLRs or mirrorless cameras), the lens directs light to a digital sensor.Six Lens Types are shown below. Plano Convex. Plano Concave. Bi-Convex. Bi-Concave. Positive Meniscus. Negative Meniscus.What are basic lenses for photography? These are the best beginner prime lenses for Canon, Nikon and Sony. Canon EF 50mm f/1.8. ... Nikon 50mm f/1.8D. ... Sony 50mm f/1.8DT. ... Canon EF-S 24mm f/2.8 STM. ... Nikon 35mm f/1.8G AF-S DX. ... Tamron 70-300mm f/4-5.6 Di LD. ... Sony 55-200mm f/4-5.6 DT. ... Canon EF 75-300mm f/4-5.6.What are the four major types of lenses? The four major types of lenses are the short-focal-length lens, the middle-focallength lens, the long-focal-length lens, and the zoom lens.