The ergonomics of the S50 are surprisingly good considering its diminutive size; the buttons are well placed and functional, and menu screens are legible and logically organized. The menu system has a nice feature for those who have difficulty reading its small font size, the ability to enlarge the font by touching the telephoto zoom control. The only issue I had with the camera's controls was a very sensitive shutter button. When shooting outdoors the LCD, with its brightness adjustment, is quite usable even in bright sunlight. Whether you're shooting in low-ambient light or capturing night scenes, the LCD "gains up" or amplifies the live image, helping you compose the shot.

Power up to first image captured measured approx. 3 seconds. Shutter lag when pre-focused is approx. 2/10 second, and about 7/10 second including autofocus time. Add about 1/10 second when using the LCD, as it delays the the live image presented on its screen. The shot to shot time in normal, single exposure mode averaged about 3 seconds without flash, and between 4.5 and 9 seconds with flash, depending on subject distance. When shooting in Continuous mode, the S50 captured images at a rate of one every two seconds, the number of shots limited only by the amount of remaining memory on the SD card. This performance was measured using a SanDisk Extreme 512MB SD memory card with the image size/quality set a 2560x1920/ , and includes viewfinder delay, photographer response time, and image capture. All times may vary depending on lighting, camera settings, media, etc.

The Pentax smc 3x optical zoom lens has a focal length coverage equivalent to 35.6mm-107mm (in 35mm format) with a 2.6x digital zoom feature. There is moderate barrel distortion at full wide angle but almost no pin cushioning at full telephoto. At full wide angle the lens exhibited considerable softness at the edges, and distant subjects were more than slightly out of focus. The S50's AF system was a poor performer in average indoor lighting because it has no focus-assist lamp.

The overall image quality in 2560x1920/ mode was below average for a 5-megapixel camera. The main problem was image softness that some would call "blurry" looking. When shooting indoors you will be limited by the minimal flash range of 11.5ft. This is sufficient for portraits or small groups, but lacks the power to illuminate average to large sized rooms. The camera comes with 11MB of internal memory but no SD memory card so you can only store about 3 of the large images before running out of memory. You'll need a larger (128MB to 512MB) size SD card to make this camera useful; the average file size of a 5-megapixel best quality image exceeded 3.5-megabytes.

Battery life was good; the S50 captured over 200 images on a pair of 2450mAh NiMH rechargeable batteries with full-time use of the LCD viewfinder. Battery power is quite versatile; you can use two one-use AA alkaline, one lithium CR-V3 or their rechargeable cousins. The latter being preferred for cost savings and of course so your local landfill can be used for more bio-degradable things.

While the Optio S50 tempts beginners with its under-$300 price tag, 5-megapixel resolution, ease of fully-automatic operation, extremely durable compact design and built-in help screens, its image quality is second rate, especially outdoor scenics at full wide angle. Its lack of a focus-assist lamp and the resulting poor AF performance indoors will also disappoint beginners. If you're in the market for an easy to use compact 5-megapixel digicam, I recommend that you spend a few more dollars and consider the SONY Cyber-shot DSC-P93 or the Canon PowerShot A95 instead.