The Alpa 10d Half-Frame (halbformat) is a 35mm SLR made by Pignons in Switzerland, a variant of the Alpa 10 series configured to expose half-frame (18×24mm) negatives rather than the standard 24×36mm full frame. Alpa cameras of this period were low-volume, hand-finished instruments aimed at the high end of the precision-camera market.

Auction data for the half-frame 10d is extremely thin: the only recorded UK saleroom result we hold is a single 2009 hammer price of £2,200, which gives some indication of the wholesale level a collector-grade example reached but is not a reliable guide to what one is worth today in 2026. Because half-frame Alpas were produced in very small numbers, value at auction is driven almost entirely by condition, completeness and provenance, and prices for comparable rarities can swing widely from one sale to the next.