We're still not sure how, but Pentax has managed to shoehorn a 5-megapixel CCD, a 5X zoom lens, and gobs of advanced features into the very compact dimensions of the Optio 550. And its images stand out from the crowd, too. If you are a serious photographer and want to cut some weight and bulk, take a close look at this Pentax. With an aluminum-alloy body and a textured silver finish, the Optio 550 is good-looking but not especially striking. It feels quite solidly built, however, and its buttons and dials operate crisply. At 8.8 ounces with the battery and the media installed, the 550 isn't exactly a featherweight, but it's no trouble to schlepp around. And its modest dimensions let it slip easily into any handy pocket.
|/sc/20851169-2-200-DT1.gif" width="200" height="150" alt="" />|
|The mode dial encircling the shutter release gives you access to plenty of manual and automatic photo options, as well as video- and audio-recording modes and special effects.|
|/sc/20851169-2-200-DT2.gif" width="200" height="150" alt="" />|
|You can select from numerous flash, drive (self-timer, continuous shooting, and so on), and focus modes via these dedicated buttons.|
Pentax did an excellent job placing the Optio 550's controls, though a handful of them are unlabeled, which confused us until we'd memorized their functions. You can access critical features rapidly via dedicated buttons or the four-way pad. When you must dive into the menu system, you'll find it nicely organized and labeled. You can easily view a dynamic histogram along with current setting information or activate a viewfinder grid with the Display button, and pressing Playback lets you quickly switch between shooting and image review without ever touching the mode dial.
|/sc/20851169-2-200-DT3.gif" width="200" height="150" alt="" />|
|You can program each of the controller pad's arrows to access a different setting when pressed at the same time as the Menu/Function button. The pad also lets you navigate menus and adjust exposure and focus.|
|/sc/20851169-2-200-DT4.gif" width="200" height="150" alt="" />|
|You can't make any quick battery or media changes when you're shooting on a tripod because the mount is right next to the hatch.|
|/sc/20851169-2-200-DT5.gif" width="200" height="150" border="0" />|
One of the 550's most admirable features is its retractable 5X zoom lens--a rarity on such a compact camera.
Exacting photographers will appreciate having the option to change image-processing parameters such as contrast, in-camera sharpening, and color saturation. And the camera's multifaceted autobracketing function can snap three-shot bracketed sequences that adjust any of these parameters, as well as white balance and exposure. Additional items include a panorama-stitching assist mode, an interval-timer mode, and a multiple-exposure feature for superimposing one image on another. You can also goof around with the camera's 3D mode, which shoots pairs of pictures that you can print and view in 3D with the provided plastic glasses.
The 550's lens covers a zoom range equivalent to 37.5mm to 187.5mm in 35mm-film-camera terms. Its f/2.8-to-f/4.6 maximum aperture is a bit narrow compared with that of some prosumer digicams, but that's part of the price you pay for the camera's small size.
You can capture still pictures as uncompressed TIFF files or as JPEG files at any one of three compression levels. We wish Pentax offered a RAW mode; RAW would do a better job than TIFF combining high image quality, creative flexibility, and fast file saving. On the other hand, annotating photos with voice captions is easy on the 550, and a dedicated audio mode enables you to use the camera as a voice recorder. The 550's movie mode captures 320x240-pixel QuickTime video with sound in clips up to 10 minutes long. And if you notice yourself channeling Charlie Chaplin, you can use the special fast-forward mode to give video a silent film's fast-motion look. Pentax does not provide a glue-on mustache. The Optio 550's performance, though adequate, isn't as impressive as its feature list. Start-up time is a middling 5 seconds, and we found overall shutter lag a bit longer than we'd prefer. That's largely because the autofocus speed is average at best. Low-light AF sensitivity, on the other hand, is pretty good. Shot-to-shot time when you're capturing JPEG files is quick at roughly 2 seconds, but with TIFF files, it balloons to a frustrating but not atypical 20 seconds or more. The camera's comparatively lackluster continuous-drive mode shoots four photos at about 1 frame per second before it pauses for about 10 seconds to clear the buffer.
|/sc/20851169-2-300-BATT.gif" width="300" height="225" alt="" />|
|We were impressed with the Optio 550's D-LI7 lithium-ion battery, which lasted for two days of heavy shooting on a single charge.|
The Optio 550's lens zooms quietly and smoothly, but you can't control its exact zoom position with as much precision as you should. In contrast, manual focus is quite precise, and the LCD shows a magnified view of your scene's center portion to help you determine the correct focus. The LCD itself is fairly sharp and usable in both outdoor and low light. We preferred it to the optical viewfinder, which is acceptably sharp but small and a bit dim. The LCD and the viewfinder show approximately 100 percent and 86 percent, respectively, of the actual image.
The built-in flash's 12-foot maximum range (at ISO 100) is a bit better than average, but there is no slow-sync flash setting. You can get around this limitation in manual or shutter-priority mode, but it's still a senseless omission. Our test images came out very well overall. Exposures, both flash and ambient, were consistently accurate. Sharpness and detail are first-rate, and the camera's photos will support good-quality enlargement to 11x14 inches or bigger.
Colors are generally pleasing and natural-looking, though yellows and occasionally blues tend to be a little undersaturated. Under indoor tungsten lighting, using the Indoor white-balance preset produced slightly cool images with a faint cyan cast, while the automatic white balance gave shots a very mild magenta cast.
To our surprise, the lens shows almost no barrel distortion at its wide-angle end and only modest pincushion distortion at its telephoto position. Remarkably few artifacts appeared in our pictures; even purple fringing, the curse of digital photography, was rare.
We did see moderate vignetting in the corners of some wide-angle photos with blue skies. This could be a problem if you shoot a lot of landscapes or architecture, but it's inconsequential for nearly all other scene types. We also noticed a smidgen more noise in our ISO 100 test shots than we've come to expect from the best prosumer models. If you can get away with a lower sensitivity, ISO 50 images are superclean. But results at the ISO 400 setting, as with all of the camera's competitors, are quite noisy.