Bokeh & Compression
Recently on an episode of Fro Knows Photo, I watched the Fro & Greg edit a RAW file of some girl posed in a sitting position on a concrete ledge with a forest type background. At the end of the show, they were critiquing the shot such that it had been taken with a 50mm f/1.8 Canon. The general gist of what was said was that the bokeh on the 50mm 1.8 was not as pleasing as it could have been had the portrait been taken with a 70-200mm f/2.8.
Now, I happen to love 50mm primes. They are almost the perfect portrait lens on crop censor cameras, producing a sweet 75mm on my D300s. In fact, my new 50mm f/1.4 G lens should be arriving any day now. So while I wait, I decided to borrow a 70-200 f/2.8 lens from Jocelyn, setup my own miniature wedding photo shoot for John & Marsha and do a “which has better bokeh” test.
There are two main things going on that we need to be aware of: Bokeh & Compression. Bokeh is the Japanese word for “stuff that is out of focus in a photo.” Compression is described as an effect produced by a long lens (longer than 35mm) that smooshes and flattens backgrounds. It gives the effect of even more buttery bokeh. There are some people who contest this as a myth though.
For simplicity’s sake, longer telephoto lenses *should* produce more pleasing bokeh because it is “compressed” in addition to being out of focus. This is where Greg was coming from on the Fro episode. So, let’s check the results of my mini-field test and you can make up your own conclusions.
The situation was that John and Marsha surrounded by background and foreground elements (pineapple, spiderplant, gerbs and a happy face flower resting on two toddler chairs and a brick wall). This simulates a wedding couple in a park area with some trees & shrubs and thick forest behind them. The lenses used were Nikkor 70-200mm f/2.8 VR, 70-300mm f/4.5-5.6 VR, 105mm f/2.8 VR macro, and a 50mm f/1.8. All the lenses were mounted on a D300s on a tripod using mirror lock up and a cable release with VR off. Light levels and ISO remained constant. Distance was slightly changed to try and maintain similar perspective.
Here is a gallery of the results:
What do you think? Which lens has the most pleasing Bokeh? Which lens produces the most pleasing portrait?