Art photography, a minimalist buyer's guide

Section 1: Image Capture

Camera: body

Fig. 2: Typical DX dSLR

Cameras are sufficiently specialized to various uses that it's almost as meaningless to recommend a camera as it is to recommend a pair of shoes (will the shoes be used for hiking, sports, casual wear, or formal?). But what if you could only own one camera, and it would have to last you at least the next five or ten years, and money is very definitely an issue – what would you buy? When I put the question like that it becomes very easy to answer: what I want is a 12 megapixel dSLR with an APS-C-sized sensor (which I'll call DX for short). I feel this is the sweet spot of the spectrum.

There are of course quite a few DX camera bodies to choose from, since every Japanese camera company makes one. And it's such a tightly-fought battle that they're all excellent choices. If you have any brand preference, based on the urging of a friend, or on marketing, or whatever, by all means go with that. If you tend to favour a Goliath over a David, go with Canon. If you can get a good deal on one of them, great. Failing any of the above, put the names Canon, Nikon, Pentax, and Sony into a hat, reach in, and choose one. Here are the options as I write this in early 2009:

If money is particulary tight or if weight is a particularly serious issue, I'd look closely at the Olympus 620, the Panasonic G1 and the Canon XSi. Image quality is not quite up to the level set by the bigger cameras, but far better than compact cameras.

A year later: The latest-and-greatest model numbers have changed at least incrementally from the above. I don't propose to keep researching then updating these; the idea is to provide a guideline, not substitute for personal research. But I'm going to finally come out of the closet on the contentious issues of brand differences:

I've never used a Canon dSLR ... and probably never will, since just from reading the specs I can see no practical way to use one for accurate metering.

Over the past few years Nikon has transformed itself into the system to beat. They have an excellent control set, excellent auto focus, and really excel at image quality. This especially includes low noise levels at high ISOs.

Pentax has even better controls, concentrates on making the smallest, toughest bodies; but in the image quality department sacrifices low noise for higher resolution (an appealing trade-off for landscape work). An area where Pentax shines is its prime lens line-up.

Sony just continues to take heat from reviewers in nearly every aspect of DX-scale camera design. The one thing they currently excel at is in making a full frame dSLR with excellent resolution at low ISOs – in other words, a very attractive traditional landscape photographer's tool.

Olympus Like Pentax, Olympus concentrates on making the smallest, toughest bodies. As to image quality, see the 4/3rds box below. Also parallel to Pentax, Olympus has a realy sterling rep for lens quality.

Rationale

As to body types: Compact/point&shoot cameras can take fine pictures in good light and when subject motion isn't a serious issue but otherwise rapidly begin to lose it. Full frame dSLRs have superb image quality and excellent responsiveness, but are heavy, bulky, and expensive without delivering dramatically better image quality. Budget DX cameras with 10 mp sensors fall short on image quality. Both the one digital rangefinder and digital medium format are extremely expensive. Film cameras remain an interesting option, but the lack of immediate feedback, the on-going cost of film and developing, and the expense of a good scanner put them in a very specialized niche.

So I argue that the DX camera represents the best all-around compromise, given our premise; but, conversely, it is contra-indicated for the following:

Making huge prints of highly detailed subject matter, such as landscapes, fashion spreads, and large group portraits
Working in extreme low light conditions
Working with rapidly moving subject matter, such as sports
Working in rugged conditions, requiring weather proofing and/or shock resistance
Working with specialized subject matter such as architecture or wildlife.

4/3rds: The 4/3 scale sensor is smaller than DX but their aspect ratio (68% of the area of a Canon APS-C sensor and 61% of a Nikon, Pentax, or Sony sensor) is closer to square than the oblong APS-C sensor's aspect ratio, which makes better use of a given size lens. At this time 4/3 sensors have roughly a stop more noise and and a stop less latitude (dynamic range) than the best APS-C sensors for a given megapixel count.

As to image quality: Since the first commercial digital cameras in the 1990s, the primary battle has been resolution. It took so long for affordable cameras with sufficient resolution for general-purpose photography to become available that a resolution-is-everything mindset became entrenched in the photographic community. We can now see that 12 megapixels (if well-implemented) are sufficient for all but the most specialized needs.

Resolution: naively we might assume that a 24 mp camera, for example, will have twice the resolution of a 12 mp camera. It's difficult to test SLR resolution, since we can't put the same lens on cameras from different manufacturers. Even so, we have to take into account that resolution increases by the square root (multiply by 1.4) of the megapixel count, not linearily, since the pixels have to cover a rectangular area. So at best a 24 mp camera would resolve 40% more detail than a 12 mp camera, not 100% more. But things are never that simple. For technical reasons camera makers put a slight blurring filter (called low pass or anti-aliasing) in front of the sensor, and these filters differ in strength and thus in detail lost to blurring. As we go to higher ISO numbers, resolution is further lost to noise at different rates, so camera X may have better 100 ISO resolution than camera Y but worse 800 or 1600 ISO resolution. Yet another issue: the greater the sensor resolution, the better the lens must be to keep up, especially when we move away from the f/5.6 to f/8 sweet spot. Finally, the greater the resolution of the sensor the better your technique has to be to keep from obliterating the gain due to camera shake.

Before digital and the battle for resolution, photographers generally understood that image quality rested on four legs:

Colour/tonal resolution (accuracy and subtlety)
Detail resolution and acutance
Dynamic range (latitude)
Sensitivity (lack of noise or grain at high ISOs).

Almost as soon as digital cameras began to appear with raw output it became clear that colour accuracy was a surprising strength of digital capture. Only recently, as high megapixel counts became common, did we see that colour subtlety is very much a by-product of high resolution. The more finely a sensor samples a portion of the scene, the more accurately it records micro-differences in hue. At present, 12 to 15 megapixels on a APS-size sensor and 18 to 22 megapixels on a full frame sensor are excellent compromises between all four of the above variables, with the lower number of each pair favouring low noise, and the higher number favouring better resolution.

It's the last two variables – latitude and sensitivity – that are the new battleground in digital imaging development. But with latitudes of ten stops and usable sensitivities of four stops (e.g.: 100 to 1600 ISO) already common in APS-C and larger sensors, we're already operating from a position of strength.

Camera: lenses

Fig. 3: Panasonic G1's kit lens

Like camera bodies, lenses are so specialized to various uses, that it's almost as meaningless to recommend a single lens.

Most camera bodies come in a kit with an inexpensive, light-weight zoom, covering moderately wide to moderately telephoto focal lengths, and relatively slow speed (maximum aperture). Kit lenses may not provide the ultimate resolution – but you may not need that; they may be rife with distortion – but much of that can be corrected in software; they may not provide image stabilization – that's an issue unless you mainly work with a tripod or in bright light.

So, given that the kit lens is the smallest and lightest way to cover the most frequently used range of focal lengths, my recommendation is to buy and use it, unless and until you know otherwise. Even if you end up regularly using another lens or lenses, the kit lens remains useful when maximum portability is paramount, as when hiking or on vacation.

For more information on lenses see my Camera lenses: a crash course.

Camera: accessories

Carrying case: one option is to buy a non-photography bag with a compartment large enough for your camera plus lens, then use this to pack your camera as well as your usual paraphrenalia. (If the compartment isn't padded, add padding yourself.) The advantage of this is that no one (including thieves) knows you're carrying a camera. Another option is to buy the smallest holster-style shoulder bag that will fit the camera and your main lens. Again mobility is key.

Memory card: buy a fast card from a big name company, such as the Sandisk Extreme III and IV series. 4 or 8 gigs capacity should be plenty to start with.

Lens hood: one comes with every lens, so it is not usually an extra purchase.

Filters: don't bother: some photographers continue to use them with digital cameras, but this is very rare.

Tripod: if you need a tripod at all, you'll know it and have no shortage of recommendations to work with.

External flash: this is a specialized tool that was much more common when working at high ISOs was not a practical option.

Studio lighting: if your approach and subject matter takes you into the studio, you'll figure out for yourself which of the vast range of studio equipment you need.

Camera: compact (point & shoot)

Many dSLR owners also own a pocket camera to have with them at all times. Nevertheless, this remains a luxury, not a necessity.

Given that art photography is intended, it doesn't do much good to have taken a usable composition if the image quality is unusably bad due to excessive noise, over/under exposure, or unwanted blur. The vast majority of point & shoots have only the most rudimentary controls and only produce JPEG output, which means white balance, contrast curve, white point, black point, and above all heavy-handed sharpening complete with haloes are baked into the image. Further, because the light sensors used in pocket cameras are a small fraction the size of those used in dSLRs, image quality rapidly breaks down in less than bright sunlight. This means shooting in twilight requires a tripod (but what's the point of carrying a tripod with a pocket camera?) and shooting indoors requires either a tripod or flash (which ruins the shot by wiping out shadows).

Fig. 3: Panasonic LX3

At present this leaves only three serious options: the Panasonic LX3, which lacks telephoto reach but is reasonably small, the Canon G10, which lacks low light capability and is borderline too large for pocketing, and the Ricoh Caplio GX200 and GR Digital III, about which I don't know enough to comment. All four do have raw output and a usable control suite.

Update Fall '09: There are now a host of new options, including:

Olympus E-P1 and E-P2. Smallish but not pocketable; E-P1 model has no viewfinder, E-P2 does. Both: interchangeable lenses like an SLR; in-body image stabilization; 4/3 sensor so somewhat more noise and less dynamic range (see 4/3rds box above).
Panasonic GF1. Same comments as E-P2 but better auto-focus; built-in flash; poorer noise and dynamic range; image stabilization in selected lenses only, not in-body.
Canon S90. Pocketable; usable 400 and 800 ISO; raw output; 28-105 zoom.
Canon G11. Requires large pocket; usable 400 and 800 ISO; raw output; hinged LCD; 28-140 zoom.

Camera: profiling

Every device in the image chain needs to be characterized for colour, else one is simply whistling in the dark. Cameras present a particular challenge because their colour output is as much a product of the external light source (and even the colour of sunlight varies radically with time of day, humidity, etc.) as it is of their internal sensor and supporting circuitry. Nevertheless, each raw converter (discussed below) has at least one profile for each camera body it supports. This assumes each camera of the same make and model yields identical output, which is known to be false, but the upside is that the profiles are made with very sophisticated equipment. An interesting new option is the xrite ColorChecker Passport.