{"overview":"The Dallmeyer 5 Inch f\/2.9 Pentac is a large-format British lens with a roughly 127mm focal length and an f\/2.9 maximum aperture. The Pentac was a fast portrait and aerial-reconnaissance type lens, and copies turn up today on view-camera and projection mounts as well as in adapted form for medium and large format use.","market_narrative":"At recent UK auction, hammer prices for the 5 Inch f\/2.9 Pentac have sat in a tight £81–£126 band, with a median around £125 based on three saleroom results between 2023 and 2026. As of 2026, that range reflects what clean working examples sell for at wholesale auction level rather than retail dealer asking prices, so a tidy copy is typically worth around the upper end while scruffier or partial examples drop toward the lower figure.","buying_guide":"Inspect the front and rear groups for fungus, internal haze and cleaning marks, as uncoated or lightly coated brass-era Pentacs are prone to bloom and wipe scratches that affect value. Check the iris for oil on the aperture blades and sluggish movement, look for separation or balsam edge-yellowing between cemented elements, and confirm the focus or barrel mount turns smoothly without grit, since many surviving copies have been removed from original shutters or projectors.","specs":"Key documented specifications are a 5 inch (approximately 127mm) focal length and a maximum aperture of f\/2.9, sold under the Dallmeyer Pentac name; further construction details are not provided in the supplied data.","faq":[{"q":"What is a Dallmeyer 5 Inch f\/2.9 Pentac worth today?","a":"Recent UK auction hammer prices have ranged from £81 to £126, so a clean working example is typically worth around £120–£125 at saleroom level, before buyer's premium."},{"q":"How much does a Dallmeyer 5 Inch f\/2.9 Pentac sell for at auction?","a":"Three UK auction results between 2023 and 2026 show the lens selling for £81, £125 and £126, putting the realistic hammer price for a usable copy at just over £100."},{"q":"Is the Dallmeyer Pentac a good value lens for large format use?","a":"At an auction price band of roughly £80–£130 it is one of the more affordable fast British large-format lenses, though the final value depends heavily on glass condition and whether it is mounted in a usable shutter or barrel."},{"q":"What should I check before buying a Pentac?","a":"Look closely for fungus, haze, cleaning scratches, oily aperture blades and any separation in the cemented groups, as these faults are the main reasons a Pentac will sell at the lower end of the price range."}],"confidence":45,"reasoning":"Only three unverified UK auction records and no SPECS or variant data were supplied, so pricing commentary is reasonably grounded but technical detail is necessarily limited."}

{"overview":"The Dallmeyer 8 Inch f\/2.9 Pentac is a long-focus large-format lens of the classic Pentac series, offering a 203mm focal length at a relatively fast f\/2.9 maximum aperture. Designed for press, portrait and aerial work on large-format plate cameras, it is a British-made optic typical of the mid-20th century era of Dallmeyer's London production.","market_narrative":"At UK auction the 8 Inch f\/2.9 Pentac is a thinly traded item, with the only logged hammer price being £88 at Chiswick Auctions in August 2024 — a wholesale saleroom result rather than a retail asking price. With just one data point, that figure should be read as indicative of what a clean but unmounted example sells for today rather than a firm market value, and condition, shutter fitment and presentation case can all shift the price meaningfully.","buying_guide":"Inspect the glass carefully for fungus, internal haze and cleaning marks, all of which are common on Dallmeyer optics of this age and significantly affect value. Check the iris for oil on the aperture blades and confirm the blades open and close smoothly, look for signs of element separation around the cemented groups, and make sure the focus mount or barrel threads turn cleanly without stiffness or play.","specs":"Key specifications from the supplied data are limited to the headline figures: an 8-inch (approximately 203mm) focal length and an f\/2.9 maximum aperture, sold as a Dallmeyer Pentac series lens.","faq":[{"q":"What is a Dallmeyer 8 Inch f\/2.9 Pentac worth at UK auction today?","a":"Based on the single recorded 2024 sale, a Dallmeyer 8 Inch f\/2.9 Pentac is worth around £88 at hammer in the UK auction market, though with only one data point the value of any individual example will depend heavily on condition and completeness."},{"q":"How much does a Dallmeyer Pentac 8 Inch f\/2.9 sell for?","a":"The only logged UK auction result shows the lens selling for £88 hammer in August 2024; clean, shutter-mounted or cased examples could reasonably exceed this, but there is not enough sales data to give a firm price range."},{"q":"What was the Dallmeyer Pentac 8 Inch f\/2.9 designed for?","a":"It is a fast long-focus large-format lens of Dallmeyer's Pentac line, a series associated with press, portrait and aerial photography where its f\/2.9 aperture allowed shorter exposures than typical plate-camera optics."},{"q":"Is the Dallmeyer 8 Inch f\/2.9 Pentac a good buy at current prices?","a":"At sub-£100 hammer levels it is inexpensive for a fast 8-inch large-format lens, but buyers should weigh the price against the cost of cleaning, shutter servicing or remounting, since these can easily exceed the lens's auction value."}],"confidence":35,"reasoning":"Confidence is low because SPECS and variant data are empty and SALES HISTORY contains only a single auction record, limiting factual grounding to the headline focal length, aperture and one hammer price."}