What the heck is Bokeh?

Aside from being one of my favourite words to say, Bokeh (pronounced boke-uh) in photography is the blur, or aesthetic quality of the blur, in out-of-focus areas of an image. The term originates from the Japanese words boke which means “blur” or “haze”, and the word boke-aji which means “blur quality”. Bokeh occurs in the parts of the scene that lie outside the depth of field. Refer to my recent post on depth of field to learn more.

When photographers intentionally use a shallow depth of field to create prominent out-of-focus areas in an image, bokeh can often appear around small highlights such as reflections or light sources in either the foreground or background of the scene.

Here’s an example of bokeh in a pair of recent pictures I snapped: (click on the image for full-size view)

Image #1: no bokeh, but good shallow depth of field

Image #2: BOKEH!

Good vs. Bad Bokeh

If the blur of an image is aesthetically pleasing to the eye and augments the overall image, it’s considered “good bokeh”. However, if the blur in an image is unpleasant or detracts from the quality of the image, it’s considered “bad bokeh”.

There are several variables that can affect the quality of your bokeh, but the biggest influence is the shape of the aperture when the image is shot. It’s because the shape of the bokeh in an image tends to look like the shape of the aperture that is passing light through.

In low-end or mid-range lenses, when the aperture opening (or f-stop) is set to less than the maximum opening, the shape of the aperture becomes a polygon rather than a circle. In some high-end lenses, there are more blades that move in and out to shape the aperture opening, so it appears closer to a circle than polygon when less than fully opened.

Five and Seven-Bladed Aperture Openings (credit: tested.com)

Equipment You Need

I’ve been experimenting with my new camera lens: Canon EF 50mm f/1.8 II. It takes really great pictures for such an affordable lens ($150). Until very recently, I had no idea how important the f-stop was to the quality of images you capture. You can spend more money to get an f/1.4, and even more to get an f/1.2. The lower the f-stop number, the better. Among other qualities, small f-stop lenses have larger and higher quality apertures. Thankfully, my f/1.8 lens was cheap, but it delivers excellent quality pictures, nonetheless.

Here’s a basic pricing comparison (as of today):

• Canon EF 50mm f/1.8 II – approx. $150
• Canon EF 50mm f/1.4 USM – approx. $500
• Canon EF 50mm f/1.2L – approx. $1,800

Great Example of Bokeh

Normally, I would only post my own work, but in this case I can’t resist borrowing from (and crediting) others. Here are a couple of other great examples of bokeh that I’ve seen:

Christmas bokeh
(credit: Wikipedia)

“Day Fifty Five” by Jnap

“A Cup of Bokeh, please?” by Shermeee

“The Fingers of Summer” by Ryan Brenizer

So, now that you know how to do it, go out and take some “bokeh-licious” photos!

In photography, Depth of Field (DOF) is essentially the Depth of Focus. It’s the distance between the nearest and farthest objects in the scene that appear acceptably sharp in the image. A shallow DOF tends to focus your attention on the primary subject of the image while effectively hiding from view the less important objects in the foreground or background. Alternatively, a large or deep DOF keeps most or all of the image in focus, allowing the viewer to see all objects in the frame.

Depth of Field / Depth of Focus (credit: Wikipedia)

Shallow vs. Deep DOF; Which to Choose?

Depending on your camera, you may have no choice. Inexpensive cameras typically take all photos with a deep DOF, and the images usually have all the objects in the scene in focus.

Shallow DOF photos are typically used in portrait or artistic photography, while deep DOF photos are typically used in applications such as landscape photography, where the scene requires everything in the frame to be in focus.

To achieve shallow DOF, you need either a lens with a small f-stop, a telephoto zoom, or a macro lens. A small f-stop lens (e.g. f/1.8 vs. f/5.6) has a large aperture, or opening, which focuses light more acutely on the optical sensor, causing objects in the foreground and background to be out of focus. You might be asking, “Why does a larger aperture cause a shallow depth of field? I won’t bore everyone with the details, but if you’re interested here’s a good forum conversation with a drawing that does a good job of explaining the physics.

Equipment I Use

Camera: Canon EOS Rebel T2i ($600 approx.)

Lens: Canon Prime 50mm f1.8 ($150 approx.)

Examples of Shallow DOF: (click on images)

Eat, Drink, and Be Irish

Good red wine from Beringer Vineyards, Napa Valley

The barrel cave, O’Shaughnessy Estate Winery, Napa Valley

Table art

Reflections

Magnolia

The Boy

Learning to Walk in the Sand