It's Always the Glass
By Ken VanBree
Today's camera market is filled with an overabundance of choices of models that can be used as a tool by architects and builders. In this month's column, I will give some guidelines on what to look for when selecting a camera that will be used to take construction photos.
Let me start by saying a few words about film cameras versus digital cameras. If you are looking for a camera to shoot high- resolution photos for use in advertising brochures and large format posters, film cameras are still the best value. But if you are looking for a camera to document your construction projects, digital cameras offer excellent image quality, ease of use and low operating costs. If, like many builders, you take thousands of pictures a year, the savings in film and development costs will easily pay for a quality digital camera within a year or two.
Several years ago, a panel of experts in photography was organized by the Tech Museum of Innovation in San Jose. The panel was headed up by a Silicon Valley venture capitalist who asked each panel member what they would look for when purchasing a digital camera. The recommendations from most panelists revolved around size, weight, ease of use and resolution of the digital sensor. But the advice from one panelist, Karen Mullarkey, has always stuck with me. Karen Mullarkey began her career as the producer for Life Magazine's coverage of the Apollo Space Program. She has directed photography departments at Rolling Stone Magazine, Sports Illustrated and Newsweek, and was the first woman to head the Photography Department at a major news magazine. She has a lifetime of experience selecting images from the best photographers in the world, taken with the best camera equipment that money could buy. When the panel's moderator asked Karen what was important to look for in a digital camera, her answer was short and to the point. She said simply, "It's always the glass."
So the first thing to consider when looking for a great digital camera is the quality of the lens. Leica lenses are legendary among photographers. Nikon, Canon, Carl Zeiss and Olympus make excellent lenses as well. An excellent lens will not guarantee that your pictures will be sharp and clear, but a poor lens can defeat all of your best attempts to clearly document your construction progress.
After you have chosen a good lens, the next question is how much resolution you need in the sensor that provides the digital equivalent of film. A pixel (a contraction of Picture Element) represents the finest detail that a digital camera can resolve. Cameras are rated by Megapixel, which is the product of the number of pixels across one side of an image multiplied by the number of pixels down the other. The more pixels your camera can record, the higher its resolution. A 3 Megapixel camera should be adequate for most of the photos that you will need to document your construction projects.
There are three types of digital cameras on the market today. At the low end of the range are point-and-shoot cameras, including the Canon Powershot series or the Nikon Coolpix series. These cameras are small and convenient to carry, and are available in a wide range of resolutions, but they are limited by the fact that most do not have interchangeable lenses. They also aren't available with lenses wider than about 35-mm. This can be a problem when photographing in tight spaces. At the top of the range are professional cameras, such as the Canon 1Ds and the Kodak DCS Pro. These are Single Lens Reflex (SLR) cameras with interchangeable lenses. They have all the features needed by professional photographers, but their $5,000 base price put them out of range for most consumers. Sitting between the point-and-shoot cameras and the professional cameras are prosumer models like the Nikon D70 and the Canon Digital Rebel, which list for just under $1000. They have most of the features of the professional models and allow you to use the same interchangeable lenses preferred by professional photographers.
One drawback to prosumer cameras is that they don't have full frame sensors. By that I mean that the area of the sensor (the digital "film" if you will) is smaller than the standard 24 x 36 millimeter frame that has been a standard for film cameras for years. The smaller sensor size means that only the center of what the lens sees is recorded digitally. This effectively increases the focal length of the lens. Nikon has standardized on a conversion factor of 1.5 for its digital SLRs. This means that a standard 50-mm lens will shoot like a 75-mm medium telephoto lens. This is an issue for construction photography because you often need to shoot in small spaces like bathrooms. A film camera using a 24-mm lens can capture an eight-foot wall from floor to ceiling from about five-and- one-half-feet away. If your digital camera has a 1.5x focal length multiplier, that 24-mm lens becomes a 36-mm lens that would need to be eight feet away to shoot the same wall. That is difficult to do in a bathroom that is only five feet wide. To solve this problem, the prosumer cameras often come with wide-angle zoom lenses. The Canon Digital Rebel is often bundled with a Canon 18 - 55- mm zoom lens, which is equivalent to a 28 - 85-mm zoom on a standard SLR. Although zoom lenses are popular, I've found that fixed focal length lenses are often lighter and give you more light-gathering power (that is, larger apertures). This is important when you are taking pictures in the low light conditions that often occur inside of buildings under construction.
April 2005 Builder Architect Edition Issue
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