Light is Everything!

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? 🙂




2 responses

  1. Ali

    Nice article, i will vote for the 105mm macro i think it’s more clear.. i have Nikon 35mm f/1.8 it is really wonderful lens for most day-time.. and i am using 70-300mm VR to.. i am not professional so sorry for my question here..

    I Have Nikon D90..
    Question plez.. How to know if i have a “crop censor cameras”?
    and Is this good??

    March 3, 2011 at 2:15 pm

    • Yes, the D90 is a crop sensor. In Nikon terminology, it is a “DX” body (D3100-D7000) while there “FX” bodies are full frame (D3s/x D700) A crop sensor is physically smaller than a full sensor (which is approximately the size of film). There is nothing bad about crop sensors, they are just physically smaller inside the camera which makes them less expensive to produce, but they do affect the focal lengths of your lenses. On Nikon it’s by a factor of 1.5. So your 35mm f/1.8 on a crop sensor actually becomes a 52mm lens. DX bodies (cropped sensor) cannot shoot as wide as full frame cameras. But they do pick up extra reach using longer lenses. A 300mm on a DX body is actually 450mm! We pick up an extra 150mm just by using a crop sensor body which is great! I will do a post on this topic to explain it better. Hope this helps. 🙂

      PS: Here’s a video that explains the differences really well: DX vs FX

      March 3, 2011 at 3:00 pm

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