Your How To Source: Issues of Value, Ethics, Human Needs and Deeds Edited by Heinz Dinter, PhD
At last, digital S.L.R.’s that won’t break your budget
About six years ago, Anthony J. Kinney bought the first of a series of compact digital cameras. Some were bigger, some were smaller, and their features were as varied as the cameras’ brand names. But one thing was constant: none of them were satisfying.
Mr. Kinney, a research scientist in Wilmington, Del., was particularly frustrated by the lag that occurred with all the compact cameras, when the shutter was pressed and the exposure was made.
“Kids move around a lot,” he said of his favorite subject, his two sons. “By the time any of the cameras took a picture, the kid would have moved out of the frame.”
Mr. Kinney’s disappointment lifted — and his digital camera buying spree eased — about a year and half ago when he bought a Canon EOS Digital Rebel, the first digital single-lens-reflex camera offered at a price (about $1,000 with a lens) that a middle-class father of two could consider.
Not only did the Digital Rebel prove to be infinitely superior to the last film S.L.R. Mr. Kinney owned — a robustly crude, Soviet-made Zenit — he said it also transformed how he took digital photos.
“The whole thing about point-and-shoots is convenience,” Mr. Kinney said. “With the S.L.R., you’re not just taking a snapshot, you’re thinking more. Ultimately that’s what makes a good picture: your brain.”
Mr. Kinney is not alone in his fondness for digital single-lens-reflex cameras, which do not yet dominate digital cameras in the way that they ruled film cameras during the late 1970s. But the success of the Digital Rebel has led to a rush by every camera maker, as well as newcomers like Sony and Samsung, to introduce digital S.L.R.’s priced and designed with consumers in mind. Nikon alone now offers four such models.
Despite their comparatively low prices (the Olympus Evolt E-500, in a package with two zoom lenses, sells for $800; and the Pentax K110D, with one zoom, sells for about $600), digital single-lens-reflex cameras help manufacturers make up for profits lost to the even steeper price drops for compact digital models over the last two years.
For camera buyers, however, determining if digital S.L.R.’s are worth the extra money (as well as the added bulk, weight and, in some cases, complexity) is less straightforward. It requires balancing those drawbacks against the cameras’ generally higher image quality, more capable autofocus, viewing and exposure systems and their ability to change lenses.
As their name suggests, digital S.L.R.’s most obviously distinguish themselves from compact cameras by their reflex-viewfinding system.
With compact models, users compose their photos either through a tiny separate viewfinder or by previewing the shot on the camera’s liquid-crystal-display monitor. (Extra-small compact cameras usually offer only the monitor.)
All S.L.R.’s, whether film or digital, let users compose by looking through the lens through a system of mirrors, lenses and prisms. That mechanism — which must quickly flip the mirror out of the shutter’s way for picture taking and then immediately drop it down again — is what accounts for most of the larger size and weight.
But it is also the feature that allows the use of different lenses. Many photographers, including Mr. Kinney, also find that it provides the most accurate preview of the resulting photo.
“The viewfinder is much bigger and brighter than any point-and-shoot,” Mr. Kinney said. “It was just such a joy to look through it.”
But arguably the most significant differences between compact point-and-shoot cameras and digital S.L.R.’s lie hidden well inside their plastic and metal shells.
The shutter lag that irritated Mr. Kinney, for example, occurs mostly from the fact that the compact camera’s imaging sensors are doing a wide variety of jobs besides capturing a photo. Chuck Westfall, the director of technical information for Canon in the United States, said that a big cause of shutter lag is the image sensor’s doing extra duty as an autofocus sensor. (The need for the sensor to switch from a preview to exposure duty when the shutter is pressed is another factor.)
In digital S.L.R.’s, however, the image sensor’s only job is to take pictures. Specialized sensors handle autofocus readings, exposure measurement and white balance (adjusting the camera’s color settings to eliminate unnatural color shifts caused by light sources other than the sun). On top of that, the larger size and higher prices of these cameras mean that they generally have more powerful computing chips to make sense of that data.
The other major difference internally is the image sensor chips themselves.
From the beginning, digital camera marketing has emphasized the pixel count of imaging sensors. What it does not say is that not all pixels are equal.
Compact cameras use much smaller sensor chips than digital S.L.R.’s. Mark Weir, the senior product manager for digital S.L.R. cameras at Sony, said that a typical compact camera sensor is “about half the size of your smallest fingernail.”
“A digital S.L.R. sensor is pretty big,” he added, “about the same as a good-size postage stamp.”
As a result, every pixel on a compact camera’s sensor chip is much smaller than its counterpart on a digital S.L.R.’s sensor. Mr. Weir, whose company also produces sensors for a number of other camera makers, estimates that pixels on a 10-megapixel compact camera sensor are about 2 microns across, compared with 6 microns for a digital S.L.R. sensor of the same resolution. A micron is one-thousandth of a millimeter.
That creates several problems. Makers of compact sensors are hitting physical limits on the ability to align the tiny individual lenses that sit on top of every pixel to concentrate the incoming light. Those tiny sensors, at the same time, place a heavier burden on lenses because the images they create eventually undergo high levels of magnification, even when viewed at snapshot size.
The only compact model with a sensor as large as those in digital S.L.R.’s is the Sony Cyber-shot DSC-R1, Mr. Weir and many others argue that the sensor size difference and the division of labor with other sensors give digital S.L.R. cameras a big edge in image quality over compact cameras.
“Digital S.L.R.’s have advantages in these areas that point-and-shoot cameras are very, very challenged to enjoy,” Mr. Weir said. “People are willing to trade off the simplicity, compactness and affordability of point-and-shoots because they’ve been in situations where their point-and-shoot camera could not get the shot they wanted.”
Bob Sanferrare, a retiree in Merrimac, Mass., owned several Nikon and Canon film S.L.R.’s over a 40-year period. But in the fall of 2001, he bought a 2-megapixel Sony compact digital camera. Its photo quality did not match that of his Nikon FA, a conventional film S.L.R. But he liked the idea of not having to take film on long overseas trips.
Six months ago, Mr. Sanferrare upgraded to a digital S.L.R., the Nikon D200. While its price, $1,700 without a lens, puts it firmly at the high end of cameras for consumers, Mr. Sanferrare chose it over less expensive models available at the time because it offered the greatest compatibility with his collection of old Nikon lenses. (Nikon later introduced another model, the D80, with similar backward lens compatibility that sells for $1,000 without a lens.)
Like Mr. Kinney, he has found that there is no comparison between the D200 and his admittedly aging compact camera.
“I don’t see any downside to the D200 except for its weight,” Mr. Sanferrare said. He added, however, that like most digital S.L.R.’s, the D200 appears to have been designed with the assumption that it will be used with autofocus lenses. As a result, it has a focusing screen that while very bright, makes it difficult to distinguish fine changes in focus when using manual focus lenses.
Although different models of digital S.L.R.’s accept older lenses from the same manufacturer to different degrees, there is still one major change when the older lenses are used on any consumer-priced digital single-lens-reflex camera, even those in which every lens feature is fully compatible.
While the imaging chips in consumer S.L.R.’s are much bigger than those in compact cameras, they are still smaller than a standard 35-millimeter film frame. (Canon makes two digital S.L.R.’s with film-size chips, but both are expensive and mostly used by professionals. Kodak offered similar cameras but has discontinued them.)
That size difference between film and chips means that lenses effectively take on different properties when used with a digital S.L.R. On his film camera the Nikon FA, Mr. Sanferrare’s Nikon 50-millimeter lens had a standard focal length, neither telephoto nor wide angle. On the D200, it is the functional equivalent of a 75-millimeter lens, making it ideal for portraits.
The smaller imaging chips allow manufacturers to design lenses for the consumer digital S.L.R.’s that are more compact than models for film cameras. Along with his D200, Mr. Sanferrare bought a Nikon 18-200-millimeter zoom lens, one that effectively goes from a wide-angle setting to one with enough telephoto power for most sporting events.
Not only is the lens (which has a suggested price of $900) unusually compact, it also contains an electronic system for eliminating blurred photos caused by camera shake.
Mr. Kinney’s Digital Rebel (which has been replaced with a new model, the EOS Digital Rebel XTi, selling for about $900) came with a zoom lens that goes from wide angle to slightly telephoto. He has since augmented that with a zoom that offers more telephoto settings and a 50-millimeter lens with a wide f1.4 maximum aperture for use in low light. Among other things, that allows him to photograph his two boys indoors without using a flash.
The greater number of digital S.L.R.’s aimed at consumers, of course, also makes choosing the ideal model more difficult.
In general, more expensive models like the D200, which overlap with the professional market, are larger and, their makers say, more robust. (Officials at Canon, Sony, Olympus and Pentax all say, however, that digital S.L.R.’s are more durable than their compact counterparts.)
Compactness is nice on holidays but not always an advantage. Mr. Kinney found the Digital Rebel too small for his hands and eventually bulked it up with an accessory battery grip.
The more expensive models also remove some features that less sophisticated photographers may find useful. Most semiprofessional models, for example, do away with settings marked by little pictographs that set up the camera for specific kinds of shots like portraits, sports or landscapes.
Mr. Sanferrare said that most amateur photographers who do not have older Nikon lenses would probably find another Nikon S.L.R. camera, the D50, much easier to use than his D200, and with little or no tradeoff in picture quality. They would also walk out of the store with $1,000 still in their pocket, as the D50 sells for just $700.
While they are more capable, digital S.L.R.’s will not solve every photographic problem.
“I definitely think that I’ve taken some of the best pictures of my life with the Digital Rebel,” Mr. Kinney said. “And some of the worst.”
Source: www.NYTimes.com • Ian Austen
comments and contributions.
Not yet a subscriber to
Grand Lifestyle published every month?
The Grand Lifestyle news journal is an email service designed with you in mind. We think you will enjoy reading it. However, if you wish to unsubscribe, please click here.
You have my 100% guaranty
for protecting your privacy:
© 2003-2006 Grand Lifestyle Publisher
| Top |