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Description: | No. 3 Series II anastigmatic patent lens F.5.4 6.5inch f.l. in a heliocal focusing mount and ring type iris diaphragm. Double Anastigmat with a field of approximately 85 degrees at the maximum aperture of F.5.4. Either front or back lens can be used on its own as a single landscape lens. Using the front combination the focal length is 1.5 x that of the entire lens while the rear combination gives a single lens with a focal length double of that of the whole lens. First introduced in 1897. Dallmeyer | License: | http://creativecommons.org/licenses/by-nc-sa/2.5/ | Subjects: | anastigmatic lens | Source: | Science Museum | Creator: | J. H. Dallmeyer Ltd | Identifier: | 1979-559/1231 | Go to resource |
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