The Cornu Ontoscope is an early French stereoscopic camera from the small Paris-based maker Cornu. It was built for paired-image stereo photography on plates, a format popular in the early twentieth century before roll-film stereo cameras displaced it.

Public auction data for the Ontoscope is extremely thin: the only verified UK saleroom record we have is a single Christie's hammer result of £70 in 2001, so today there is no meaningful current price band to quote. Anyone trying to work out what a Cornu Ontoscope is worth in 2026 should treat that figure as a historic data point rather than a guide to what the camera sells for now, and watch upcoming specialist stereo sales for fresh comparables before assigning a value.