Here we are on Black Friday. Before you rush off to the temple of consumerism, please heed these tips on digital cameras, especially if you plan to be photographing food. Today we'll talk lenses.
- macro focusing or closeup mode (or “food mode”)
- a wide angle lens
- a “fast” lens
- flash that’s easy to turn off (and stays off!)
- ergonomics you like
Wider is better
For whatever reason, the consumer camera industry puts a lot of attention on the long end of the zoom. More telephoto must be better. 3x zoom!, 5x zoom!! For my purposes, the other end is the important one - how does the lens perform for wide and close work? Think about it - you're sitting in a restaurant and want to photograph the plate in front of you. Do you have to stand up or take a step away from the table to get the whole plate in the frame? If so, your lens isn't wide enough.
In 35mm terms, most compact digital cameras have lenses that start at around 32-38mm focal length. That's on the wide side, but I strongly prefer 28 or even 24mm if possible. If by chance you find one wider than that, be careful as wider lenses can make things look more distorted as they get super-wide.
But compact digital cameras are not 35mm, so unless they declare their "35mm equiv" lens dimensions, you are more or less on your own since there's no single conversion factor. Here's my rule of thumb: look for six or less. If the tiny numbers on the front of the camera's lens begin with a number lower than 6, it's nice and wide. For example, one camera I looked at has a lens marked 6.1-30.5mm f/2.8-4.5 and has a 28mm equivalent wide end. Another has a 5.9mm lens that's also listed as 28mm equivalent.
Another less well-known benefit of a wide lens, especially in low-light situations, is that it's less sensitive to shaky hands than a longer lens. Which leads us to the next lens tip...
Faster is better
"Faster" in this case is pretty archaic terminology, but trust me when I say that it means you can take better pictures in lower light. How do you know how fast a lens is? Let's go back to the numbers on the lens, for example:
This means that we're looking at a zoom lens, one that goes from 6.1 to 30.5 mm in focal length, meaning the actual focal length, not necessarily the focal length in familiar 35mm terms. The second set of numbers are the maximum aperture at those extremes - f/2.8 at the wide end, and f/4.5 at the telephoto end. F/stop?? Don't panic. It's just a number that says how big the hole that let light in is. Bigger numbers after the f/ mean smaller holes. Smaller numbers mean bigger holes, which also means faster.
Right. Smaller numbers after the f/ are faster and better. Since we're generally most concerned with the wide end of things, I recommend worrying only about the first f/ number. There's no particular cutoff, but 2.8 is nice to have. Numbers lower than that are rare on consumer cameras. Numbers higher than 4.0 make me nervous - that means the camera lets in half as much light as one with f/2.8, and that can be a big difference when you're only working with a candle in a dark bistro. The second number will always be a good bit larger than the first on a zoom lens, so don't panic if its up there.
So let's summarize. For best food photography, we're looking for a camera with a lens with no more than 28mm equivalent wide end (or less than about 6mm in digicam terms) with an f/ number as low as we can find. The long end of the zoom won't matter much shooting food, so don't sweat it. All of the above applies only to optical zoom. Digital zoom doesn't help the wide stuff, so ignore it.
In the unlikely event that you find a camera without a zoom lens - one that has just one focal length and just one f/number - I advise you to consider it seriously if the numbers are good. Non-zoom lenses, or "primes" as they are sometimes called, almost always have superior optical properties to zoom lenses set to a similar length. They focus closer and faster, when your're photographing food in the wild, that's what you need.
Next time, flashes and ergonomics...