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Most of the time, you don’t notice your blind spot. That’s the point where the optic nerve connects to the retina. Your eyes, on the other hand, have a blind spot. How else are your eyes different from a camera?īecause a camera has photoreceptors all over its lens, it always sees a “full” picture. There are no rods at all at the centre of the retina. In the human eye, however, the cones are concentrated at the centre of the retina. The photoreceptors in a camera are evenly distributed across the lens. Cameras respond to red, blue and green light using filters placed on top of their photoreceptors. Colour blindness affects people whose retinal cones don’t work properly.Ĭameras also have photoreceptors. When your brain activates different combinations of cones, you can see the world in colour.Ĭolour vision deficiency is often called colour blindness. Location of rods and cones and how they react to different wavelengths of light (Let’s Talk Science based on an image by Graphic_BKK1979 via iStockphoto). Green cones respond to medium wavelengths. Each type responds to different wavelengths of light. They aren’t useful for colour vision.Ĭones let you see in colour. Your retinas contain two types of photoreceptors: rods and cones. How does an eye process colour differently from a camera? Mechanical parts in the camera lens also adjust to stay focused on a moving object. That’s why photographers change lenses, depending on how far away they are from an object. It is able to do this because the lens is attached to small muscles that contract and relax.Ī camera lens can’t do this. The thickness of the lens also changes to accommodate the image being viewed. The lenses in your eyes change shape to stay focused on a moving object. How does an eye focus differently than a camera? The second relates to how they process colour. The first relates to how they focus an image. There are two major differences between the human eye and a camera. Film is transparent so you can view the images on it the right way around. Non-digital cameras contain a prism or mirror that flips the image so it appears right side up. Digital cameras are programmed to make the correction on their own. It knows the world is supposed to be right side up. This is because your brain steps in to help your eyes. And the movies you watch aren’t upside-down either. This flips the image upside-down.īut you don’t see images upside-down. When light hits a convex object, it refracts. Why? The lens in both an eye and a camera is convex, or curved outwards. They all receive an inverted (upside-down) version of the image. Retinas, film, and imaging sensor chips all have one other thing in common. An SLR camera has a lens (1), mirror (2), aperture (4), prism (4), film or imaging sensor (5) and eyepiece (6).