Pentax has been very focused in its approach to the DSLR market, having targeted the under-$1,000 price range exclusively. At the beginning, the company's original *ist D was the least-expensive DSLR in the game. In the past year, Canon's Digital Rebel and Nikon DSLR models usurped the rock-bottom-price position, but then, with the K100D, Pentax can argue added value.
This is the only 6MP DSLR currently to offer an in-camera shake reduction system. Pentax has always had a good sales argument, and through the K100D they extend that argument a little further.
You've probably noticed that 6MP, once thought to be the upper limit of CCD capacity, is now practically entry level among DSLRs, 10MP having become this year's standard. In terms of actual size, the difference between a 6MP and a 10MP picture is not that great. But it sounds like a lot, hence a stampede to the higher number.
Indeed, the K100D is the final 6MP DSLR, their 10MP K10D having already hit the market. Nevertheless, Pentax tells us that the K100D will remain current through the spring or summer, maybe later, so there will still be a variety of choices and a passel of explaining when customers come in and ask, "Which is the best DSLR for my money?"
And if the discussion confines itself to the current 6MP models, the shake reduction of the K100D makes it a serious contender. Shake-reduction systems are real benefits—not panaceas when it comes to picture-taking at slow shutter speeds, but certainly a powerful ally.
Steadying Up on Shake Reduction
It's clear from the evidence—newspaper advertisements especially—that in-camera shake reduction isn't universally understood. One Sunday-supplement insert from a large electronics chain, for example, illustrated the value of shake reduction with a young boy bouncing on the living room sofa. It made a charming picture, but was absolutely misleading as a depiction of what shake reduction does.
Shake reduction can't do a thing about the blur caused by subject motion when the shutter speed's too slow. With or without shake reduction, that kid on the couch will turn out smeared in the picture, unless flash is used or the ISO is cranked up to a degree that permits a sufficiently fast shutter. Either could "freeze" the bouncing kid, but neither has anything to do with the shake-reduction feature.
What in-camera shake reduction (and image stabilization as found in various individual lenses produced by Canon, Nikon, Sigma, et al) can accomplish is a compensation for camera movement at slow shutters; subject movement is a different issue.
Most people can't hand-hold a camera steady enough at a fifteenth of a second, though most can at a sixtieth. If the anti-shake system produces a steadying influence equal to two EVs (which all seem to, at the very minimum), then hand-holding at a fifteenth becomes the equivalent of hand-holding at a sixtieth. People can do it. The kid may still be a blur, but the sofa itself will be sharp.
It's probably handy for the retailer to be a little proactive in a demonstration of cameras equipped with shake reduction or anti-shake, or image-stabilization features. Get it into your spiel that the system corrects for camera shake only. It's an important clarification.
Lots of cameras besides DSLRs have various forms of image stabilization, and it's particularly valuable in those with high-performance (10x+) zoom lenses permanently built-in. Telephotos magnify everything—subject, camera shake, you name it. Wide-angle lenses do the opposite. They're less prone to suffer from camera shake, but not invulnerable.
The value-added story becomes more significant, as the customer considers additional lenses. If any lens benefits from anti-shake, it's even better without the extra cost when it is built into the camera.
The Other Steadying Factor
Another solution to motion blur is to crank up the ISO so a faster shutter can be used. This is practical in many cases. Although picture noise generally increases as ISO equivalencies increase. Changing the ISO from one picture to the next is one of the great innovations of digital photography, and in league with image stabilization, it permits taking pictures that would have been unthinkable before.
A lot of cameras can reach ISO 800, 1600, 3200, but many can't do it very well. The trade-off can be between blur from motion or fuzziness from noise, also known as "the frying pan or the fire." Unless the camera has unusually low noise characteristics at the higher ISO settings.