Pentax's ultra-compact 4MP Optio — 35-105mm equiv sliding-lens zoom, 1.8in LCD, D-LI8 battery, 2004
The Pentax Optio S4i was announced in February 2004 as an update to the Optio S4 in Pentax's line of ultra-compact digitals, the family famous for fitting inside an Altoids tin thanks to the sliding-lens design Pentax introduced with the original Optio S. It carried the same name in all markets.
A 4-megapixel 1/2.5-inch interline CCD sits behind an smc Pentax 5.8-17.4mm 3x zoom, equivalent to 35-105mm, which retracts one lens group sideways to collapse the body to 83 x 52 x 20.5mm. The 1.8-inch TFT LCD shows a 100% field of view. The built-in flash offers auto, on, off, red-eye reduction and slow-sync modes. Storage is SD/MMC plus 11MB of internal memory, and power is the proprietary D-LI8 rechargeable lithium-ion pack.
Its selling point remains sheer pocketability: a genuinely tiny metal-bodied camera with a useful 35mm-equivalent wide end. Controls are simple and automated, aimed at snapshot and travel use rather than enthusiast control, and the small sensor means results are best in decent light.
Used examples hinge on the D-LI8 battery, shared across many Optio models, so replacements and chargers are still easy to find. Test the sliding lens mechanism carefully — it must extend and retract without grinding, as the folded optical path is the model's known mechanical weak point. Check the small LCD for damage and look for dust spots in test shots; SD/MMC card support means no obsolete media worries.