{"overview":"The Dallmeyer 51mm f\/1.9 Oscillograph is a specialist fast prime from the long-established London optical maker J.H. Dallmeyer, built for recording cathode-ray oscillograph traces onto film. Its wide f\/1.9 aperture was designed to capture faint, fast-moving phosphor images rather than for general photography, and the lens is typically encountered in industrial or laboratory-style barrel form.","market_narrative":"At UK auction the 51mm f\/1.9 Oscillograph has shown a wide spread of hammer results, ranging from £200 up to £2,000, with the bulk of recent 2024 sales clustering between £850 and £1,625 and a median close to £1,237. As of 2026 these wholesale saleroom figures reflect what clean, complete examples sell for before buyer's premium, and condition, completeness of mount hardware and glass clarity appear to drive most of the variance in what the lens is worth.","buying_guide":"Inspect the elements carefully for fungus, haze and cleaning marks, as specialist industrial optics often sat unused in humid labs for decades. Check the aperture blades for oil and sluggish action, look for separation or cement yellowing between cemented groups, and confirm the focus or mounting collar turns smoothly; because this lens was made for oscillograph rigs rather than a standard camera mount, verify that any adapter or flange supplied is correct and undamaged.","specs":"Key published specifications are limited to a 51mm focal length and an f\/1.9 maximum aperture, with the lens identified by Dallmeyer as an Oscillograph objective.","faq":[{"q":"What is a Dallmeyer 51mm f\/1.9 Oscillograph worth today?","a":"Recent UK auction hammer prices have ranged from £200 to £2,000, with most 2024 results falling between £850 and £1,625 depending on condition and completeness."},{"q":"How much does a Dallmeyer 51mm f\/1.9 Oscillograph sell for at auction?","a":"Clean examples have sold for around £850–£1,625 at recent UK sales, while a rougher copy sold for £200 and an exceptional result reached £2,000 back in 2015."},{"q":"Why does the price and value vary so much between copies?","a":"Because this is a specialist industrial lens rather than a camera lens, value swings sharply with glass clarity, smoothness of the iris and focus, and whether the original mount or flange is present."},{"q":"Is the Dallmeyer Oscillograph usable on a normal camera?","a":"It was designed for oscillograph recording rigs, so using it on a stills camera requires a custom adapter, and buyers should confirm mount details before bidding."}],"confidence":45,"reasoning":"Only four sales records are available and SPECS\/variants\/facts are empty, so confidence is capped at 50 per the rules."}

{"overview":"The Dallmeyer 76mm f\/2.8 Oscillograph is a specialist fixed-focal-length lens made by the long-established London optical maker J.H. Dallmeyer. As its name indicates, it was designed for oscillograph and instrumentation recording work rather than general pictorial photography, capturing cathode-ray traces and similar high-contrast subjects at close to 1:1 reproduction.","market_narrative":"Today this is a niche industrial lens with a thin auction record, and hammer prices for clean copies at UK auction have ranged from £69 to £119, putting the median around £94. Because it lacks a standard photographic mount and a wide buyer base, even tidy examples sell for modest sums at saleroom level, and condition matters far more than provenance to what it is worth.","buying_guide":"Inspect the elements for fungus, internal haze and cleaning marks, since instrumentation lenses often sat in laboratories for decades before being decommissioned. Check the iris for oil on the blades and confirm the aperture ring moves smoothly; also look for separation around cemented groups and verify that the barrel mount is intact, as adapting one to a modern camera is the main practical hurdle.","specs":"Key specifications from the supplied data are limited to a 76mm focal length and an f\/2.8 maximum aperture, with the lens designated by Dallmeyer as an Oscillograph type for instrumentation use.","faq":[{"q":"What is a Dallmeyer 76mm f\/2.8 Oscillograph worth today?","a":"Recent UK auction hammer results sit between £69 and £119, so a typical clean example is worth roughly £90–£100 in the current market."},{"q":"How much does a Dallmeyer 76mm f\/2.8 Oscillograph sell for at auction?","a":"It sells for a two-figure to low three-figure sum, with the two recorded UK hammer prices being £69 and £119 depending on condition."},{"q":"Why is the price so low for a Dallmeyer lens?","a":"The Oscillograph was built for scientific recording rather than pictorial photography, so demand is limited and the value reflects its specialist, non-standard-mount nature rather than the strength of the Dallmeyer name."},{"q":"Is it usable on a modern camera?","a":"Only with custom adaptation, as it was supplied for instrumentation rigs rather than a common camera mount, which is one reason hammer prices stay modest."}],"confidence":35,"reasoning":"Only two unverified sales records and no detailed SPECS or variant data were supplied, so factual grounding is thin and confidence is capped accordingly."}