Pentax's 2003 compact flagship - 5MP 1/1.8-inch CCD, 5x optical zoom, SD/MMC storage, D-LI7 battery.
The Pentax Optio 550 was announced in February 2003 as the flagship of Pentax's Optio compact line, combining a then-high 5-megapixel resolution with a 5x optical zoom in a pocketable body. It preceded the closely related Optio 555 and shared its era with the 4-megapixel Optio 450.
It is built around a 5-megapixel 1/1.8-inch interline-transfer CCD producing images up to 2560 x 1920, behind a 5x optical zoom. Sensitivity runs from ISO 64 to 400, movies record at 320 x 240 and 15fps for up to 10 minutes, and files save to SD or MultiMedia cards. Power comes from the proprietary D-LI7 lithium-ion battery; the body measures 101 x 58 x 42mm and weighs 230g.
With a bigger-than-average sensor for a compact of its day and a longer zoom than most rivals, it suits collectors of early-2000s CCD compacts and casual shooters wanting more reach than the typical 3x pocket camera. The modest ISO ceiling and 15fps video make it a daylight stills camera.
The D-LI7 battery is long discontinued, though third-party cells and chargers are still made - confirm a working battery is included and holds charge. SD/MMC storage is easy to supply, but the camera predates SDHC, so use a small-capacity card. Check the telescoping zoom extends without grinding and the CCD shows no streaks.