The point-and-shoot cameras are great, that is, as long as the subject of the photo is not moving very fast. But if the photographer is trying to catch the moment that the little soccer player kicks in his first goal or when the black Labrador leaps in the air to snag the Frisbee, then he may find a picture of an empty field or a blue sky. The compact digital camera can take so long to react after you snap the shutter release button that the moment has passed and the desired image is never captured.
The problem is called shutter lag. “It’s the No. 1 dissatisfier that we hear about,” said Bob Gann, Hewlett-Packard’s digital imaging systems architect. But avoiding it, or minimizing it in the next camera you buy — well, that is a tricky problem.
About 65 percent of camera buyers are buying their second or third digital camera, but this time they probably will not be focusing on the number of megapixels as they did in past purchases. (Anything over 5 megapixels is going to provide the resolution any amateur photographer needs.) Instead, they might want to think about how well that camera takes pictures, including the action shots.
The problem is, camera makers do not want to tell consumers too much about that. It is not that they have anything to hide; it is just that shutter lag is too difficult a concept to communicate in ads or marketing materials in stores. “No kidding, I am trying not to geek out,” said Jerry Magee, product manager at Kodak.
It still is much easier to sell consumers on a camera’s price, style, color, image-stabilization abilities, wireless ability or even its many preset shooting modes like fireworks, underwater or dining. “Our emphasis is on finishing their pictures and making them as good as possible right in the camera,” said Steve Heiner, a senior technical manger at Nikon.
That said, “there is a little bit of a war for a camera that can take a picture quicker,” Mr. Magee said.
The first problem is that shutter lag is not really shutter lag at all, but processor lag. (Feel your eyes glazing over already?) When the photographer begins to push down the button to snap the picture, sensors in the camera begin to take a series of measurements. The processor calculates the distance to the object, determines the amount of light needed and even does some balancing for color and whiteness. The processor may also have special software to focus on faces, so those calculations are run. In effect, the processor is analyzing a series of images as the button descends.
Then the image is captured on the processor and sent into memory.
That can take almost as long as one second. So any consumer who wants to buy a fast-acting camera merely has to look at the specification sheets, right?
Well, no. Many cameras’ spec sheets do not list any number that would help a consumer make a choice. The Nikon Coolpix S500, which the company said was one of its best performers for action shots, gave no clues. The Hewlett-Packard $230 Photo Smart R837, its best contestant, lists only “shot-to-shot time” of 1.5 seconds. (Some reviews said it had “shutter lag” of 0.37 second.) The Kodak EasyShare Z712 IS has a “click-to-capture” speed of 0.26 second.
The specifications surrounding lag are not standardized and can be interpreted in various ways. Indeed, there is not even one standard. For instance, one might measure shutter lag in auto focus and another with manual focus, which will be much less. For example, Nikon brags that its S500 has shutter lag, in “release priority mode” — that is, from the time the button is half-pressed down to the point it is completely depressed — of just 0.005 second.
A shopper might find shutter speed listed. But that alone is not very helpful. “Shutter speed is just one element,” said Chuck Westfall, a spokesman for Canon. “As long as it is reasonably fast, it doesn’t make much difference.”
Better proxies for estimating shutter lag are autofocus lag and shutter-release lag if you can find that data. A conscientious shopper may find the information in reviews in camera magazines or camera Web sites. (Hint: Google the camera name and the words “shutter lag.”)
(If you already have a camera, a rough do-it-yourself test is available at www.shooting-digital.com/columns/schwartz/shutter_release_test/default.asp. But it is influenced by how fast your reflexes are.)
Another measurement that plays into catching action shots is ISO. It is a term that was transported over from silver halide film, when it measured the fineness of the grains on the film, hence its sensitivity to light. A higher ISO could capture action better in low-light conditions.
So the higher a digital camera’s ISO settings, the more able it is to nail the action shot. The $300 Kodak Z712 IS, for example, goes up to 3200.
“It might not be shutter lag, but it could be the camera system may not be robust enough to capture it,” Mr. Magee said. If true, that presents an even bigger problem for consumers: they have to evaluate the quality of the chip inside the camera, a difficult job because information about the type and maker of the processor is not readily available.
Some camera magazines refer to the processor, but camera buffs who write for them tend not to be electronic engineers who can describe the advantages of a Texas Instrument chip over a Zoran chip. “I’m not sure the customer needs to know that much about the processor,” Mr. Heiner of Nikon said.
The shutter-lag problem is not true of all digital cameras. The digital single-lens-reflex (S.L.R.) cameras do not have a problem with shutter lag. Indeed, if someone takes a lot of action photos and is really bothered by shutter lag, the solution is to spring for a more expensive digital S.L.R. model.
The good news is that the lowest end of this category has touched the upper end of the compact camera category. The Nikon D40, that maker’s cheapest digital S.L.R., sells for about $530. A Sony DSCH9/B, a 7-megapixel point-and-shoot, albeit a pretty fancy one, goes for about $480.
Photographers offer a few tips on capturing action shots with point-and-shoot cameras. If you can anticipate a shot — for instance, the birthday cake candles about to be blown out — then push the shutter-release button down halfway. Priming the auto-focus gets the process started early. When you push the button down all the way, the camera can process the information more quickly.
Another trick is to point the camera to where the action will occur, push halfway, and when the action occurs, push it all the way. That means you do not follow the subject, you follow the event. In other words, if you are tracking a downhill skier slaloming through a series of flags, aim at the flags, not the skier.
Camera makers also suggested using the burst mode, which quick-fires a series of photos. Shoot the first one in advance of the event and then you probably will capture the significant moment.
Many cameras have a pets or children mode to capture those things that will not stand still when instructed. “It works pretty well when you have enough light,” Mr. Westfall said.
As cameras simultaneously drop in price and add more features, concerns about shutter lag will diminish. “Give us a few more years and you won’t be hearing about it,” Mr. Gann of Hewlett-Packard said. “But it adds costs. We know how to make it faster, but it would cost money.”
