The Dallmeyer 10 Inch f/4.5 Portrait Anastigmat is a large-format brass-and-glass portrait lens from the long-established London optical maker J.H. Dallmeyer. With a 10-inch (approximately 254mm) focal length and an f/4.5 maximum aperture, it was designed for studio portraiture on plate and large-format cameras, where its long focal length and wide aperture suited flattering head-and-shoulders work.

Auction evidence for this Dallmeyer is thin: the only confirmed UK auction hammer result on file is £336 from November 2018, which sets the single reference point for what this lens sells for at saleroom level (hammer prices exclude buyer's and seller's commission). With just one data point, the current 2026 market value for a clean, working example is best treated as broadly in that region rather than a defined range, and condition, completeness of flange, and glass clarity will swing the price materially.