The Contessa Sonnet Tropen (Tropical) in 6.5x9 cm format is a folding plate camera built for use in hot and humid climates. Tropical models of this era were typically finished in teak or polished hardwood with brown leather bellows and brass fittings, distinguishing them from standard black-leather variants.

UK auction hammer results for the Sonnet Tropen 6.5x9 are thin, with recorded sales of £420 and £700 — a wholesale range at saleroom level that excludes buyer's and seller's commission. With only two data points spanning more than a decade, today's value of a clean example is difficult to pin down precisely, and condition of the wood, bellows and brass is the dominant price driver.