The Way of Bokeh

Is your photography stuck in a rut, or at least in need of a "shot in the arm"? Do you habitually stop down to a small aperture to derive greater Depth Of Field, in an effort to "keep everything sharp"? If so, then simply remember the mantra: "Open Wide!" and apply its exhortation. Base your artistic designs around not only what is in sharp focus, but also what's appealingly blurred.

Become an "explorer of light", experimenting with various lenses to determine how they defocus the background and/ or foreground. Beauty is in the eye of the beholder... and beautiful blur in the design of the lens and the way it is used! Read on to find out how to "get the look"...

Ethereal Effects

Always leaving modern cameras in Program Mode results in pictures that look like everyone else's. How boring! By taking back control of the aperture setting, we'll see how you can make your images really stand out from the run-of-the-mill snapshots. Look at Image 1 (Luminous Roses): using a fast (f/ 1.4) normal (50mm) lens at its widest aperture, I moved in to the lens' closest focusing distance of 0.5m. This resulted in a very limited zone of sharp focus, allowing what I term a "creamy, dreamy" effect to determine the overall mood of the picture.

Not always easy to achieve a satisfying result, but when you do, you'll feel a tremendous sense of joy and accomplishment.

Background Blur

Of the many criteria by which a lens' performance can be judged,  the principal one used most often is that of "sharpness". Yet, of considerable importance is not just how sharp in-focus subject matter  looks, but how aesthetically pleasing the out-of-focus areas appear.  With their cultural sensitivity, awareness and appreciation of nature, aesthetics, art and beauty, the Japanese have a word for the subjective quality of these out-of-focus regions. "Bokeh" is a transliteration from the two Japanese characters "bo" and "ke"-  together forming bo-ke  - which is most commonly written with an "h" at the end to assist with the pronunciation; this is "bo" as in boat and "keh" as in kettle.

A complete, fully satisfying photo incorporates the out-of-focus expanses as an integral part of the whole (like Yin and Yang, existing simultaneously throughout the universe). These "fuzzy bits" support and enhance what is in focus. For the Japanese,  "negative space" - the areas between and around the solid elements - in a picture is (rightfully) considered as being equally important as the objects themselves, in an abstract sense. Here in the West, bokeh isn't often given the significance it properly deserves. Perhaps that's because bokeh is very much subjective, that is, what's delightful bokeh to one person may be objectionable to another.

A practical consideration exists behind the lack of magazine articles on bokeh: it's easy to see in a picture, but difficult to describe with words! Consider Image 2 (Leaf's Edge). Here I've placed critical focus on the rimlit leaf, allowing the red blossoms in the foreground to become an amorphous blob; there is also background bokeh in existence with this composition. How would you verbalise all that's going on?

Also, in magazine reviews, it's much easier to test for - and quantify -  such parameters as lens resolution, a la: "The XYZ resolves 127 line pairs per mm at..." Given the appropriate optical test bench (and know how) someone else could repeat those tests and (hopefully) achieve the same measured results. But, how to express - yet alone agree upon - a highly elusive entity? To our Western way of thinking, it doesn't seem scientific; for some, bokeh is almost in the realms of mysticism.

Image 3 (Lone Begonia) provides a further example of background bokeh, as applied to a busy background. Looking closely at the lower left-hand corner of the frame in Image 4 (Sakura - Cherry Blossoms), you will notice what the Japanese term "ni-sen" bokeh. This is where lines in the (intended) out-of-focus parts of the image seem to split into two (such as the thin branches). Interestingly, Images 1 to 4 were all taken with a Zuiko (Olympus) 50mm, f/1.4 OM series (manual focus) lens. It's readily apparent that considerable scope exists to control the appearance - and subsequent emotional impact - of your pictures, without needing to spend big dollars on, say, Leitz (Leica) glass.

To better appreciate bokeh, you can start by carefully looking over your favourite pictures. Could it be you like these images so much - in part - because of the bokeh, yet hadn't, till now, been able to "put your finger" on exactly what it was which made them stand out?

Exploiting Bokeh

Cinematographers just love employing bokeh effects, with shooting their movie lens at its widest aperture. Consider how many scenes you can remember where the protagonists, in the foreground, are in sharp focus, while those distant city lights are a gorgeous, smooth blend of large, defocused, multi-coloured circles. This technique is applied so often with movies because it's effective, and, evocative of atmosphere.

You can do the same with your images. For the most dramatic display of bokeh, use a very fast lens. In the 35mm format, this means a 50mm (normal, or standard) lens, of maximum aperture f/ 1.4, at least. This is a full three stops faster than a typical zoom with an aperture of f/ 4 when set to a 50mm focal length. You ought to be able to pick up a "fast fifty" relatively inexpensively, as most photographers have abandoned prime (fixed focal length) lenses in favour of the convenience of zooms.

Image 5 (Tropical Red)  shows results from a 40-year-old Canon lens. Its main limitation is a bigger closest-focus distance compared to more modern optics, meaning I couldn't approach my subject quite as closely. This lens is manifesting some ni-sen bokeh in the top right hand corner of the frame. Too much detail is being resolved where lack of focus ought to exist; notice how the horizontally-running leaf's vein is "merged" into the red blossom in front of it. Our clue as to the cause of this "bad behaviour" is the single water droplet on the other horizontal leaf's edge, which has been rendered as a disc with its periphery brighter than the centre. For what most people would consider "ideal" bokeh, the circle of confusion (blur circle) ought to be brightest in the centre, fading smoothly out to the edges.

Does this imply the old Canon is a "bad" lens design, in terms of its bokeh characteristics? Not necessarily. It isn't usually possible to devise a lens with nice bokeh both in the foreground and  background simultaneously; there's inevitably trade-offs. Besides, the bokeh varies - for a given lens - with such things as:

* Distance from the lens to the scene's various elements; * Focus distance setting; * Aperture setting; * Nature and direction of light source.

Mathematically, Leitz optics typically have a Gaussian distribution of light intensity across the blur circle; unsurprisingly, they have achieved a cult-status following for their "look".

I also experimented with a 50mm, f/1.4 in the last lens range of Canon's manual mount. For me, the bokeh was nice and smooth, which is precisely what I wanted to achieve.

Macro Mania

A macro lens (or extension ring) achieves magnification by allowing you to get in very close to your subject. This results in extremely narrow Depth Of Field, often measured in mm (or fractions thereof!) even if that lens is stopped down considerably. Image 6 (Glowing Orchid) shows the bokeh from a 100mm, f/4 macro lens. Not as dramatic as a fast 50mm lens, due to the slower speed of the macro lens; less light-gathering capabilities means smaller display of bokeh. Due to stopping down, it is possible to count the number of blades in the lens' diaphragm (from the polygonal shape of bright out-of-focus highlights). For this lens, it is six.

Telephotos, Too

A long focal length lens (e.g. 200mm) is of great value in isolating your subject from its background. Here, also, it's important that your lens have "nice" behaviour for the out-of-focus areas. Otherwise, rather than help set off your intended subject against an indistinct background, you'll have distracting elements there which will compete for the viewer's attention. Note that zooms which are slow at their long end (e.g. f/ 6.3) won't yield strong bokeh, since more of the background remains in focus.

In Image 7 (Water Lily), the circular, defocused water droplets on the lily pads reflect the rising sun's rays and add a "sense of place" to this portrait (I'm sure Monet would have approved). Image 8 (Bird of Paradise) illustrates how smooth background bokeh can really enhance a floral portrait.

Image 9 (Viola Fantasia) is a "slice of the scene" approach to a "group" portrait. I attempted to convey an impression of the overwhelming number of blossoms by focusing partway in, with maximum aperture. Hence, both foreground and background become expanses of out-of-focus colour.

For even more "compression" of the image planes, a zoom lens set to 300mm was utilised in Image 10 (Delicate Cyclamen). Being limited in its maximum aperture, dramatic bokeh isn't expected; however, you can see how there is a smooth gradation between the in-focus foreground and the out-of-focus background (an important consideration).

Art by Design

With most paintings, everything on the canvas is equally sharp; further emphasis might be given to the main subject by means of stronger and/ or different colour, for example. Photography's  great strength in the visual arts is in the ability of the camera's lens to focus selectively.  This is similar to the characteristics of our human eyes.  Consciously incorporating bokeh into your images can really grab your viewers' attention.

The Wide-Open Advantage

It's true that most lenses give their best optical performance when stopped down about three stops from their maximum aperture. However, there are some compelling reasons for cranking the aperture as big as it will go. Of these, the most potentially rewarding  are in the domain of artistic control:

* Any out-of-focus highlights will be recorded on film as a circular shape, rather than being modified by the aperture blades; * The point of precise focus will be very clearly differentiated, thereby forcing the viewer's eye to be drawn to it instinctively; * Your photos can now take on a radically different look than you were probably used to before, creating other pathways to individualised  expression.

Too Much of a Good Thing?

Lens designers go to great lengths to minimise optical aberrations in order to improve the "numbers" for that lens, making it a more readily marketable item. However, this may well result in less-pleasing, or at least different, bokeh. Certain lenses in a particular manufacturer's line can be very sharp, yet too harsh for use in real picture-taking situations. Hence, they earn a bad reputation amongst the photographic community. A lens intended for portraiture, as an example, would ideally exhibit smooth, "mushy" background blur.

Trust your eyes - and the photographic evidence - instead of published specifications (which are based on two-dimensional test charts, rather than the real world).

Not Just Flowers

Although I've chosen flowers for consistency in illustration of the points being made, the concepts and principles of bokeh apply to any subjects e.g. street photography and cityscapes. I have taken many portraits which benefited enormously from an awareness of bokeh.  For certain landscape work, architectural details, and so forth, you'd probably still want sharpness all the way throughout your image, but then, maybe not always...

Chasing Rainbows?

Is it really worth all the effort to concern yourself with bokeh? Yes... if you wish to be more consciously in control of the emotional effect of your images on those people who view your work. If it's some aesthetic ideal, which you're driven from within to pursue, then bokeh is one more implement in your artist's toolkit that you can skillfully employ in your endeavours to approach that goal.

Bokeh: How Important?

Nikon have a series of "Defocus Control" lenses, allowing you to vary the out-of-focus characteristics as you wish, optimising for either foreground or background bokeh. Other manufacturers have started making a big (marketing) deal about how many aperture blades their lenses have (more is better). My (antique) Rolleiflex Twin Lens Reflex has more blades than I can even count; would the clever German designers have gone to so much trouble (and expense) in achieving a perfectly circular aperture if it didn't make any difference? More important, though, is the lens design itself: the simple and venerable (100 year old) Tessar lens formula retains some residual spherical aberration at close to wide open aperture. This helps the bokeh. Perhaps that's why, in part, this Zeiss lens has achieved legendary status.

Summing Up

Today's world desperately needs mystery and beauty. You can experiment with - and achieve - both these qualities in your images through utilising the unique effects possible with bokeh. When contemplating the purchase of your next lens - whether new or secondhand - consider its bokeh characteristics, along with all the other usual selection criteria. If you can't find published photos taken with that lens, you will have to put a roll of film through a camera with that lens affixed. Make a series of pictures, using different backgrounds (such as relatively bright light sources), at varying subject, foreground and background distances, and apertures from wide open to slightly stopped down. Use your own eyes - and heart - to guide you as to whether the lens is sufficiently sharp and contrasty, as well as having pleasing bokeh, for your preferences and the style of pictures you wish to make with it. Happy image-creating!