My Former Obsession with Shallow Depth of Field
It’s a trap that especially beginning photographers fall into: the obsession with shallow depth of field and the so-called “3D pop” effect that comes with it. This obsession may have something to do with an equally strong lust for fast glass, which is associated with “professional” photography. The irony is that, originally, fast lenses were not developed to achieve a shallow depth of field, but rather to gather as much light as possible, enabling photographers to use slow, fine-grained film (around ISO 100), which provided more detail and was cheaper than fast but grainy film (say, ISO 400 and above). To a great extent, this has become a non-issue because nowadays camera sensors show only minimal levels of noise — the digital equivalent of film grain — at high ISO sensitivities (up to at least ISO 1600). Therefore, fast lenses are now not only used to achieve maximal light gathering, but also to play with depth of field as a creative feature.
The thing is that this creative feature tends to get grossly overused very quickly. That typically starts when beginner photographers purchase a relatively affordable 50 or 85mm lens with a large maximum aperture (for example, f/1.4 or f/1.8) as a supplement to the zoom lens that their camera is bundled with (which probably has a variable maximum aperture that is much narrower, for example: f/3.5 at the wide end of the zoom range and f/5.6 at the telephoto end). Such a large-aperture lens gives ample opportunity to throw the subject’s background out of focus when used wide open, especially at a relatively short focusing distance. This tends to work well when shooting portraits because it isolates the subject from the background. It is this much desired “pro” look that may also give beginners the delusional feeling that they are making progress with their photography. As a consequence, they tend to shoot wide open all the time. I have done this as well. Abundantly.
Shallow depth of field should not be a goal in itself, but rather a means to an end.
Gradually I have come to realize, however, that this approach is not always desirable. Shallow depth of field should not be a goal in itself, but rather a means to an end. It should be used intentionally — for example, if the background is not important or if it is distracting. For environmental portraiture, obliterating the background is pointless because it omits an essential part of the story. Some background blur may work to draw attention to the subject, but the visual elements that surround the subject need to remain recognizable to make their story complete. Thus, the photographer needs to decide how much the subject should stand out from the background and how much background detail is needed to arrive at a balanced and compelling visual narrative. This may require either stopping down the aperture for more background detail (greater depth of field) or opening it up for less detail (shallower depth of field).
A complicating factor is that different camera systems give different degrees of control over depth of field. The larger the sensor, the more control you have over depth of field, especially at medium focusing distances, where there is enough room for relevant background elements. This means that full-frame, medium-, and large-format systems provide progressively more control over depth of field than cropped-sensor systems, such as Micro Four Thirds and APS-C. Given the exact same composition and aperture number, the larger-sensor systems provide a shallower depth of field than the smaller-sensor systems. When using smaller-sensor systems, there are two ways to make the depth of field shallower: by getting closer to the subject or by using a lens with a larger maximum aperture. Getting closer to the subject changes the composition and gives less room to the subject’s surroundings, which is not desirable for environmental portraiture. Lenses with maximum apertures larger than f/1.4 are rare because of design limitations, and if available, they are often expensive because they are specialty lenses.
I happen to own two lenses with particularly large maximum apertures. One is the Zhongyi Mitakon Speedmaster 35mm f/0.95 Mark II for my Fuji X APS-C system. The other is the Voigtländer Nokton 40mm f/1.2 for my full-frame Sony Alpha system. Both are manual-focus lenses, which makes them compact and relatively affordable (especially the Mitakon, which is designed and made in China). Both perform very well in terms of sharpness and have a distinct character as to how they render out-of-focus blur (also known as bokeh). Most importantly, both provide great control over depth of field at medium focusing distances, which is ideal for environmental portraiture. At f/0.95, which is an exceptionally wide aperture, the Mitakon provides a depth of field that is comparable to an f/1.4 full-frame lens, given the 1.5-times crop factor. That same crop factor gives it a 50mm field of view in full-frame terms. Where f/1.4 is pretty standard for a full-frame lens with this focal length, developing an APS-C lens with the same depth-of-field characteristics is a technical challenge that comes with compromises in terms of image quality and handling. The Voigtländer, with a maximum aperture of f/1.2, still provides slightly more control over depth of field than the Mitakon simply because it is used on a full-frame system that does not come with a crop “penalty.”
Below are three example photos of my daughters, all shot wide open with the Mitakon, the Voigtländer, and the Fujinon XF 35mm f/2 R WR, which I haven’t mentioned yet. The depth of field in the first photo may be tad too shallow, but in the second and third photo, it looks well balanced to me. The latter two photos also leave more room for the background, which has a pleasing out-of-focus blur while being plenty recognizable. Looking at these two photos now, I must admit that I really don’t need a full-frame system to achieve the necessary pop in my portraits. In many — if not most — cases, enough pop can be achieved with a 50mm equivalent lens at f/2 on my cropped-sensor Fuji system. This means that my obsession with shallow depth of field has gone by now. I still like the look, but only if applied thoughtfully.
Three environmental portraits of my two daughters taken at wide open apertures. The first is an older portrait of my youngest, and was shot with the Mitakon 35mm at f/0.95 on a Fuji X-Pro2 camera. The second is a recent photo of my oldest daughter, and was shot with the Voigtländer 40mm at f/1.2 on a Sony A7 III camera. The third, finally, is a portrait of my oldest at a much younger age, and was taken with the Fujinon 35mm at f/2, again on the Fuji X-Pro2 body.
