Friday, May 25, 2012
I acquired a new lens a couple of weeks ago, and yesterday I put it through a battery of tests. Along with pointing it at a brick wall and banging off a few photos to see how well it resolves tiny nooks and crannies, I decided to take photos of Jazz, our dog, lying beside the window in our dining room—a real-life situation. The lens is sharp, produces pleasing color, and it renders straight lines true. (The table leg visible in the lower right-hand side of the frame is actually crooked.)
The lens is a 50mm macro prime. It utilizes an optical design that has been around for over thirty years. Its main purpose is for copying documents and photographs on a camera stand. Being a macro lens, it is able to focus on items as small as a postage stamp so that it fills the entire frame. This lens is also perfectly well suited for general photography. It is not fancy. It is not sexy. Unlike a zoom lens, it simply stays put at one focal length—50mm. In the days of 35mm still photography (think Leicas and old Nikons loaded up with Kodachrome), photographers referred to a 50mm lens as a "normal lens" because the field of view is the same as what a normal human eye sees. This is the first prime lens that I have used on my digital 35mm (dSLR) camera. It mimics the human eye in the same manner it would on a film camera.
Normal vision for humans differs greatly from normal vision for dogs. Dogs see the world differently than humans for many reasons. Some are:
The picture below approximates how a dog will see me from the vantage point near my dining room window. The image is fuzzy, the colors are muted, the field-of-view and aspect ratio are wide, and the view is close to the ground. The furniture up close is out of focus to simulate farsightedness.
Jazz is 10.5 human years old. She is a senior dog. Her eyes are milky; she has cataracts. The picture below is a close approximation of how I think she sees.
I plan to blog more about how dogs see. Stay tuned. My next installment on dog vision will discuss motion detection, depth perception, flicker rate, and more on snout length and nearsightedness.