There are few things in life that I find more interesting than digital cameras, and also few that I find more frustrating. I don't think there's ever been an exciting new technology that's seemingly so simple and yet is so thoroughly misunderstood and misrepresented.
In past columns I have wondered why manufacturers of digital cameras act as if a digital camera were no different from a film camera as a digital cellphone is from an analog one. This couldn't be farther from the truth. You don't need to know anything about cellphone technology to use one--analog or digital--but you need to know a good deal about computers and digital imaging to use a digital camera. A digital camera is to a film camera as a pad and pencil is to a keyboard. Both let you commit ideas to writing, but one requires that you know the keyboard and computers and the other does not.
I'm also perplexed at the industry's apparent inability to create a digital camera that's easy to use. When I look at all those little buttons, dials, discs, menus and icons that make up the "user interface" of a modern digicam, I cannot help but wonder who designed those things. It's as if the powers that be wanted to save money and get things done cheaply rather than start with a blank slate and some new ideas. As is, too many digicams look as if someone began with a film camera and then grafted a digital interface onto it. The results, for the most part, aren't pretty. With all due respect to the makers of today's digital cameras--some of which are terrific and amazingly powerful devices if you can figure them out--there probably isn't a single digicam on the market today with an interface that truly makes sense, one that looks as if someone really thought about how to merge the capturing of images through high quality lenses with the power of the computer.
But enough of past rantings. The way things are going, I'll have plenty of opportunity to revisit them in future issues.
What I want to address this month is the foolishness and shortsightedness surrounding the megapixel hype. Megapixel, of course, means millions of pixels and describes how many pixels a digicam can capture. To give a simple example, a computer screen set to standard VGA resolution displays 640 by 480 pixels, or 0.31 megapixels. Doing the same math reveals that a 800 x 600 SVGA screen displays 0.48 megapixels, and a 1024 x 768 XGA screen 0.79 megapixels. What that means is that a picture taken with a digicam in one of those three resolutions will exactly fill the entire screen of a monitor set to that resolution. If you use an 800 x 600 SVGA screen to view a 1024 x 768 image, you will only see part of it unless you use your imaging program's zoom feature. If you want to display that picture on a web page, you will need to resize it down so that it fits onto a web page and so that it doesn't take forever to download. This means that if all you want to do is take pictures to display on a web page, you rarely ever need more than basic 640 x 480 resolution.
On the other hand, if you want to create paper prints from your digital images, more is definitely better. How many pixels per inch you need to get a good, photo-like picture when you print it out depends on the kind of printer you have. A good rule of thumb is about 200 pixels per inch. This means that the 1024 x 768 XGA image that gloriously fills your entire 17-inch screen only has enough pixels for a 5 by 3.8 inch print. In order to get a glossy 8 by 10, you therefore need a digicam that can capture more pixels--1600 x 2000 pixels, to be exact, or 3.2 megapixels. Now you can see why digicams are advertised and hyped by how many megapixels they have.
This wasn't always so. Early digicams were sold primarily by what size image they could create on a computer screen: VGA, SVGA, or XGA. Once image capturing technology advanced to a point where a camera's CCD could go beyond 1024 x 768 there really wasn't another computer acronym that could describe the higher resolution and manufacturers began using the term "megapixel." Digicams capable of capturing 1280 x 960 pixels were the first to break the megapixel barriers, and that's when the dam broke.
Ever since, digicams have been sold by megapixel just as Wintel computers are sold by the speed of their processors in Megahertz, as in a "800MHz Pentium III." 1.4 megapixel cameras were quickly replaced by a new generation that could generate 1600 x 1200 images for 1.92 megapixels. Then the two megapixel barrier was broken, and the latest standard is 3.34 megapixel, or 2048 x 1534 pixels. Three megapixels pretty much gets you that magic eight-by-ten print. If, of course, you have a printer that can generate output that large. If you don't, and if all you want to do is take pictures for your website, three megapixels don't matter at all. In fact, all they do is fill up your storage card more quickly and cause you extra work when you have to crop and resize all those big images.
Unfortunately, the marketing mavens have latched on to megapixel as the yard stick of a digicam's value, and what a convenient yardstick it is. Buying a digicam with less than whatever the latest megapixel standard is is like buying a PC with last year's chip. And since megapixels, like megahertz, are a moving target, whatever you buy now will surely be obsolete next year or even next month. You'll then have to buy a new digicam to keep up with the Jones's. In other words, marketing has found a way to obsolete digicams just as they found ways to obsolete PCs. That's bad enough for consumers who have to shell out money to replace a perfectly good camera, but even worse for professionals. Who will be happy with a $5,000 two-megapixel professional digital camera when every department store sells cheap consumer digicams with twice or four times the megapixels? What the marketing types don't realize is that picking megapixels as their main selling tool could prove to be very shortsighted. First of all, cameras are not computers. Once you go past a reasonable resolution, megapixels cease to matter. And unlike the ever increasing bloat of Windows that soaks up whatever new power Intel provides, the pixels in an image are simply physics. There is a limit as to how many you need Good optics, a good user interface, and good battery life, on the other hand, never cease to matter.
If you need further proof of how foolish it is to sell digital cameras by megapixels, there is a great example in the computer industry. When was the last time someone had to buy a new Palm Pilot because the old one wasn't fast enough?