This is why some digital SLRs are advertised as "full frame" models--their sensor is the same size as a frame of 35mm film, and so the lens behaves exactly the same. Of course, this magnification effect can be both good and bad. If you love telephoto photography, you'll like using a digital SLR, because all of your old 35mm lenses automatically have more "reach." But by the same token, it's harder to get the most from a really wide angle lens on a digital camera, because all lenses are somewhat magnified, reducing the wide angle effect. As a result, folks who love fisheye and wide-angle photography tend to gravitate towards the relatively small number of full-frame cameras on the market.

My wife used a cheap digital camera to take this photo of our daughter-in-law washing her dog. This is how it came out.

So how did water get bent? I'm a professional photographer and I can't figure it out!--John Brown, Salem, Massachusetts

You've stumbled onto a fascinating glitch that has caused endless confusion for camera phone owners. Inexpensive cameras, particularly camera phones like the iPhone, use something called a rolling shutter. Due to the way the rolling shutter works--capturing the image one row of pixels at a time, sort of like the way an old-fashioned TV would display video--you can get some really funky photos. This photo, which captures spinning airplane blades with an iPhone, is one of the more famous illustrations of this problem.