Nikon's 2003 3MP consumer compact — 1/2.7" CCD, 38-115mm equiv 3x zoom, CompactFlash, AA batteries.
The Nikon Coolpix 3100 was a 3-megapixel consumer compact announced in February 2003 together with the 2-megapixel Coolpix 2100. It brought a smaller, friendlier body and a new menu system to Nikon's entry range and became one of the brand's high-volume sellers of the era, later succeeded by the SD-based Coolpix 3200.
It carries a 3.2-megapixel 1/2.7-inch CCD and a 3x Zoom-Nikkor with a 38-115mm equivalent reach at f/2.8-4.9. The 1.5-inch LCD is joined by an optical tunnel viewfinder, and a wide spread of scene modes handles exposure decisions. Storage is on CompactFlash Type I cards, transfer is over USB, and two AA batteries power it, giving a kerb weight of about 215g with cells and card fitted.
The 3100 works for anyone after an inexpensive taste of early-2000s CCD imaging in a pocketable, AA-powered body. Output at base ISO is crisp enough for small prints and web use, with the saturated colour these Coolpix CCDs are noted for; there is no manual exposure control, so enthusiasts wanting to tinker should look further up the range.
Survivors are cheap and common on the UK used market. Test that the lens deploys without error messages, look for LCD bleed and scratched viewfinder optics, and check the CF slot pins carefully — it predates SD, so factor in a CompactFlash card and reader. Corroded battery contacts from long-stored alkalines are the most frequent fault; otherwise fresh AAs usually bring these straight back to life.