This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
I recently got my hands on one of Canon's finest lenses, the EF 70-200mm 2.8L IS II. The lens is one of those white bazooka-like tubes sometimes spotted along the sidelines at sporting events. Mine, in fact, was purchased to photograph roller derby.
The 70-200 2.8L is, in essence, a giant funnel for photons. It is meant to capture action, at a distance, in relatively low light. As a bug photographer, though, I've been experimenting with the lens outside of its comfort zone, focused as close as it can go.
(Yeah, I'm dangerous that way.)
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
The effect of a wide-open 70-200 2.8L at minimum focus distance is like nothing I've seen. Have a look:
The out-of focus light comprises what's called "bokeh", and each lens confers a unique quality related to the configuration of the internal lenses and the shape of the iris. The bokeh from the 70-200 IS 2.8L is so smooth as to resemble a painting!
Here's another example with the lens stopped down a bit further:
If you're having trouble visualizing what I mean by bokeh, consider the oddly pentagonal backdrop spots from a Canon EF 35mm f/2.0 prime lens:
A different lens, a completely different quality to the unfocused backdrop!