Bokeh for Dummies

"Bokeh":
- a Japanese word - the transliteration of a Japanese word for "blur" - describing the subjective aesthetic quality of out-of-focus areas of an image projected by a camera lens.  (I stole this from Wikipedia) 

"Bokeh for Dummies":
- a layman's interpretation - concerning the out-of-focus area of an image - How silky smooth is it?  How pleasing is it to the eye?    How seamlessly does it seem to transition from the in-focus area of the image?  (I stole this from one of my own brain cells)

My definition is technically not correct.  But art isn't always about the technicalities.  So if you are so inclined to learn all the technical aspects of bokeh, read this or this or this or even this.   At the end of the day, I'm really not very interested in the technical aspects of bokeh.  However, I'm greatly interested in the subjective aspects of bokeh.  Because art really is subjective in the end, isn't it?

Just for fun, I decided to try a very unscientific experiment with a couple of my own lenses to explore this subjective side of the whole bokeh concept.   I used the Canon 85mm f1.2 prime lens and the Canon 24-105IS f4.0 zoom lens set at approximately 85mm.  I set the same shutter speed for each comparison image and used an f4.0 aperture on both lenses.  Below is a sample from the test (click thumbnail for a larger image).   

All of the images can be seen in the Bokeh Test Gallery

The results were predictable from the standpoint that the 85 prime lens seems to offer a smoother transition from in-focus to out-of-focus areas in the image.  It also seems to have a softer, silkier bokeh versus the zoom lens.  The comparison images are a good way to look at the details, but what I find more enlightening is to flip back and forth between the full sized images in the Bokeh Test Gallery and get an overall experience of the difference.  For me, the 85 prime's bokeh just feels easier on the eyes. 

Something interesting to note is that even though each comparison photo was shot with the same shutter speed and aperture settings, the zoom lens produced a noticeably darker, more contrasty image.  In this way, it's not helping itself in the bokeh contest. 

I'm not sure if these results will hold true with all of my primes versus my zooms, but I intend to explore this further. 

Comments

[Craig Persel]

Thanks for these test sample. Interesting difference in the darker/contrastier zoom qualities. Have to think about that one a bit.