Good, Bad and the Ugly – What about Bokeh
Bokeh ? . . . the Japanese word for Blur . . . the word Boke or Bokeh was popularized in photo magazines and books between 1997 – 98. You will find it a common effect when using 35mm medium telephoto or Zoom lenses between 70 ~ 300 mm, and less among lenses below 50 mm, although there are some newer wide angle lenses capable of achieving some blur at wide open apertures. Not all Bokeh is aesthetic or pleasing to the eye. For the rest of this blog I shall use the Japanese word for “Blur” . . . Some lenses have more-pleasing out-of-focus areas. “Good” bokeh is especially important for Macro and Telephoto lenses, most often these lenses produce a shallow depth of field (DOF), Good Bokeh is important in the 35mm lenses used for portraits (70 ~ 135mm) because it allows separation of the subject from the background. When using a long lens of 70 ~ 200mm with a Large aperture of 2.8 will give you a very shallow DOF as seen in the above photo. As the aperture gets smaller the DOF gets deeper and more of the foreground and background are in focus. Lastly how the mechanical construct, type aperture and composition of glass, coatings & focal length all contribute to how the Bokeh handles contrast between light and dark. The primary out of focus area is composed of points of light and if one examines closely these points they are the rough shape of the Lenses aperture and how clearly each is defined is a a function of aperture size and DOF the lens has at its maximum aperture. The following three photos show the same scene, camera set to manual with AF off and mounted on a tripod. Each shot using different apertures and the 300 mm f/4 lens, the distance was focused to the closest subject distance, and the background was roughly 20 feet away. photo (A) is focused at 5 foot and an aperture of f/5, (B) is at about 10 feet aperture f/4 and (C) is focused on the leaves. This is just to show the varying degrees of Bokeh obtained by one aperture and the lens focused to different spots between foreground and background.
You will notice photo (C) has very little in focus (DOF), those beautiful soft circles in (B) are caused by the shape of the aperture.
Now looking at what a telephoto lens can do when you open the aperture to it’s widest, if using a zoom with a smaller maximum aperture try increasing the distance between your subject and the background to get good separation to make you subject pop from the background. A quick look through any sporting magazine and you’ll see how the sports photographer is using DOF & Bokeh (Wide aperture) to separate the subject from the background.
What have we learned so far that effects or produces Bokeh ? (1) Focal length, (2) aperture size, (3) aperture shape . . . all in all it is the out of focus area and how it looks. Bad light or extra contrasty lighting can affect the way bokeh looks. It can cause some nasty looking highlights, poor lens design can also render the out of focus areas to be ugly an not soft and creamy . . the latter description of soft & creamy best describes the bokeh achieved by the legendary Nikkon 85 mm 1.4 lens which is a mainstay of glamor, portrait photographers as well as the 200 mm f/2 Nikkor . . the Nikkor 70~200 mm f/2.8 is a mainstay of almost all pro’s and most pro sports photographers use 300 mm f/2.8 and 500 mm f/4 lenses shooting them wide open (biggest aperture) or 1 stop down to keep the subject separated from the background.
We’ve talked about the Good and the Bad bokeh . . but what about the Bad? well some lenses are just not capable of good blur and when it happens you will know it because it is just UGLY, it is distracting, highlights suck, and yes, even those lenses that are capable of great bokeh can produce UGLY bokeh.
Can you imitate blur, yes, some have mastered it most have not, fake DOF and bokeh just looks funny but software is getting much better at imitating what one can do in camera at the time the photo is made, you can improve it somewhat with lenses such as the 300mm f/4 Nikkor by adding a 12mm extension ring, just remember this also makes you loose infinity focus but it does increase your close focusing ability and as an added benefit you have this soft creamy background that is just crushed kind of bokeh like in the above photo. Here are some tricks you can use . . get as close as you need to your subject while adding distance between your subject and the background, especially if you are forced to shoot at apertures of f/5.6 or f/6.5 . . this will let those background items turn into soft colored blobs. Lastly you can control how your subject pops by paying attention to your background and by just a simple move of the camera a few inches one way or the other you can control the location of shapes as well as their dominance in the scene behind your subject. Well did I succeed in confusing you . . if I did then it’s time to do some reading on your own, and some practical field work (meaning get off your butt and set your camera to Aperture priority mode and select the BIGGEST F-stop like 2.8 or 4.5 and shoot only at that aperture) learn how it affects the photo. Next study how it looks in various lighting scenarios, back lighting, front lit, subject in shade and background in hard light . . as for reading do a Google search about Bokeh and some of the other things like DOF . . . playing is the key.
Depth of Field (DOF) and bokeh are just some of the tools you learn to use when painting with light and taking a shot to the next level. The object here is to get you to think and play with your camera, to understand how it behaves in different light at different settings is the way to learn and expand yourself. Push to the next level and your photos will show it. I will add a link to my 365 Project so you can study how the shot is affected by various lighting conditions with one lens and almost all shots are done from one position unless otherwise noted, the camera is tripod mounted, at the kitchen window shooting into the yard with mostly side lighting, morning and evening time frames. The aperture for most shots is between f/5 & f/6.5 . . shutter speed is varied as well as ISO.
here is the link . . . my 365 Project on Google
Have fun, if you liked this please share it with friends and leave me a comment . . .
Tim . . . aka Digipainter