Analogue vs. Digital, Mechanical vs. Electronic

Analogue vs Digital: Eye-like colour

The digital camera is not a purely digital device. The sensor at its heart is in fact an analogue device. Instead, a digital camera is digital because the analogue signal from each pixel of the sensor is digitized (assigned a numeric value) before being recorded.

The human eye is not a purely analogue device. An incoming photon strikes a single cell in the retina, which may or may not be in transmission mode at any given moment. Even if it is in transmission mode, it has a threshold such that a certain number of photons have to arrive before the nerve cell "fires". Film behaves similarly, and in any case becomes digital if scanned, which is now by far the more common case.

In years past there was much talk about a certain digital look (as exaggerated in Fig. 2); and it was possible to point to certain characteristic weaknesses of digital images. Today the main visual clue that an image comes from a digital camera is a purity of colour that comes from the absence of film granularity. In other words, digital images (excepting budget digital cameras) have come closer to matching the standard set by the human eye than film does.

Fig. 1. Normal digital image: 217 different colours

Fig. 2. Colours halved to 109

We got to this level of goodness, not only because of improvements in sensor design, but crucially due to improvements in the component that digitizes the analogue signal from the sensor. Essentially, a digital camera can now make distinctions between one colour and another that are at least as subtle as the human eye can distinguish, as in Fig. 1; and because of this our brains no longer tell us that something is missing, as in Fig. 2.

For this and other technical reasons, many are now proclaiming that digital is "better" than film. They may well have a point so long as they limit their discussion to photography as documentation. As soon as we move to photography as art, "better" becomes an aesthetic decision, and all bets are off. Artistically, for example, many feel film grain in a photograph is analogous to brush strokes in a painting, and the idea that the painting with less visibility of brush strokes is "better" than one with more visibility of brush strokes is more nearly the opposite of the truth.

What we can say is that digital capture has passed a milestone such that anyone who wants to use it for artistic purposes is no longer forced to accept limitations in colour subtlety if he chooses not to do so.

Mechanical vs. Electronic: Plays like a violin

The harpsichord hath its charm, but the piano superseded it by providing the player more control over loudness/softness. Both are something like digital in that the player is forced to a maximum of three steps, for example, when going from A to C (A to B flat, B flat to B, B to C) – nothing between the two notes is available. This sacrifice is a compromise taken to permit playing multiple simultaneous notes and in multiple key signatures. The violin makes no such compromise: the player can smoothly slide from A to C, covering all frequencies between those two notes, not just three (such a slide is called a glissand).

What the art photographer wants from a camera during the act of taking a picture is a maximally expressive instrument. The closer a camera handles like a violin does, the more expressive potential it has. Part of what makes the violin expressive is its ruthless simplicity of design. Only four strings, one bow, and no frets – about the only simpler musical instrument with glissand capability is a child's slide whistle (and of course the human voice).

The obvious analogy to the violin among cameras is the all-manual 35mm rangefinder, exemplified in the Leica M-series and the Voigtlander Bessa. Once mastered, such a camera lends itself to a truly exquisite expressiveness:

Fig. 3. City Lunch Counter, Copyright Walker Evans, 1929

Adding a zoom lens to such a camera, is about as nice an analogy to the musical glissand as one can get. Adding aperture priority and shutter priority exposure modes begins that slippery downhill slope toward automation – about which see below.

Fig. 4. Hale County, Copyright Walker Evans, 1936

However, one anti-expressive aspect of the 35mm rangefinder (or any other film camera) is the lack of in-camera playback. Taking a picture with a film camera is very much like not being able to hear yourself play until a recording has been produced and you can sit in front of a sound system to hear what you sounded like. The feedback delay inherent in film photography tended to augment the emphasis on static images, such as Fig. 4.

Fig. 5. GO commute #8

It is certainly possible to take a fluid picture such as Fig. 5 with a film camera; the dramatic advantage of a digital camera comes both in learning to gauge the effects of slow shutter speeds and in being able to immediately determine that a given image was successful so no re-take is needed.

So digital capture has the potential to actually enhance the expressiveness of the medium of photography. The problem arises when the camera interface becomes so complex that it takes several days just to read the manual. Much of this complexity is simply there to allow the photographer to tailor the camera to his particular needs. If he wants exposure increments of 1/3 stop instead of 1/2 stop, he sets this in the menu system and leaves it alone henceforward. If he wants continuous autofocus instead of single autofocus or manual, he flips the focus switch to the continuous setting and leaves it there henceforward.

It is perfectly possible to set a modern digital SLR to operate just like a 35mm rangefinder, with the exception of not needing to crank a film advance lever. Put the camera in M (Manual) mode, set the meter to centre-weighted, use manual focus instead of autofocus, turn off the playback monitor, etc.

But a more useful form of simplification might be to take advantage of the available automation and let the camera do the rote things it is capable of, freeing the photographer to concentrate on composition. The problem is that very little such automation is actually reliable, even in the most expensive cameras. The most obvious instance is exposure. Digital capture moves us past the flexibilities of the Zone System; there is now almost always one and only one optimal exposure for a given scene. The idea of multi-metering is very much to find that optimal exposure without the photographer's involvement ... the only problem is that it doesn't work.

Fig. 6: Rangefinder simplicity (Leica M4-P)

Fig. 7: dSLR complexity (Pentax K20D)

So now the photographer has the added complexity of having to deal with such things as colour balance that weren't part of the film camera experience, while not being freed of the considerable burden of exposure metering at the same time. This is something like having to clutch through all the gears of a semi while trying to drive Formula One. Or to go back to the musical analogy – it's like having to fuss with stops and pedals in addition to bowing and fingering, when playing a violin.

Nevertheless, it's not as though we're having to bow more furiously to play at the same tempo. The added complexity of today's cameras – at least some of them – bring added expressive potential along with them. We can now work in colour with as much accuracy and subtlety as formerly we could in black & white. We can shoot without tripod at light levels approaching candlelight where once the limit to handholding was pretty nearly daylight at high noon. We can change focal lengths without changing lenses. Etc.

That said, one trick to mastering (as opposed to simply using) a camera is to eliminate as much complexity as possible. When shooting landscapes in the traditional style, following the steps touched on above to turn a modern dSLR into something very like an all-manual camera is probably a very good thing to do. I have the focus mode switch on my camera set to single auto and taped down to that position because the sort of photography I do never requires any other option. Many a photographer might similarly tape the mode dial to A for aperture priority, a very easy place to live.

None of which will turn today's plastic wonder-cam into a tool one can bond with like a well-trained hunting dog or a well-worn Leica M3. But it does help to get the job done.

The other "trick" to mastery, of course, remains practice, practice, and more practice. Therefore, my next project will be to write a complete set of scales and arpeggios for the digital camera. ;) Get out your metronomes, folks, and hire a mother substitute to enforce the hour-a-day regime. Jascha Heifetz said: "If I don't practice one day, I know it; two days, the critics know it; three days, the public knows it." My last batch of pictures seem to be reminding me I haven't practiced in a full month.