Coffee Beans Close


Canon EOS 5D, 50mm + 25mm Extension Tube @ f/8, 1/30 sec., ISO 250.

I've recently been doing some work with a 25mm extension tube giving space between my camera body and its lens. There are no optics involved, just air. The Canon EF 25mm Extension Tube maintains all electronic communication between the camera and lens, for autofocus and aperture settings. This does a couple of things. First, by moving the lens further away from the digital sensor plane it causes the focusing distance to be shortened. Meaning that objects can now be put into focus much closer to the lens than they could otherwise. In the case of the 50mm f/1.4 lens, the minimum focusing distance shifted from 1.5 feet to roughly 3 inches. The compromise, however, is that the lens can no longer focus to infinity. Rather, the maximum focusing distance is chopped down to about 5 inches. Yes, this brings incredible constraints on practical usage, but the intent here is to gain macro capabilities. This is the second major shift that an extension tube brings, magnification. Objects will now be recorded larger on the sensor since they are significantly closer to the lens and in focus. A whole new world unfolds under macro photography. Not only can small subjects and details fill an entire image, but the mundane can easily be turned into abstractions and compelling art.