9/23/2023 0 Comments Spencer fingerprint magnifierThe use of the postal code dates it to after 1940. Although all of its advantages were mentioned, it was not specifically promoted as a fingerprint magnifier initially the box with this instrument does list it as a 'Fingerprint Magnifier' and is identical to the box for the next instrument on this page. Both B & L and Spencer called these magnifiers 'Utility Magnifier' without the slot in the foot to accept the Henry inserts, and 'Fingerprint Magnifier' when the slot was present.īAUSCH & LOMB 4 1/ 2 power magnifier on horseshoe base: Bausch & Lomb advertised this magnifier no later than the second quarter of the twentieth century. Magnifiers with lenses nearly identical to these are still sold today by companies specializing in forensic tools, but the quality of the B & L and Spencer models on this page were never surpassed. Obviously these instruments were well suited to other purposes. Such magnifiers were available in the early twentieth century and soon were promoted for the purpose. An achromatic aplanatic lens combination with large aperture and good eye relief would fit this requirement. Ideally a magnifier for examining finger prints should provide a sharply focused and flat wide field with a magnification of about 4 1/ 2 X and avoid the need to be close to the lens so as to limit fatigue. FINGERPRINT MAGNIFIERS: SECOND TO THIRD QUARTER OF TWENTIETH CENTURY DESCRIPTION
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