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OPTICAL LANTERNS, ETC. THE "WIGMORE" Anastigmat Projection Lenses The use of high-power electric projection filament Lamps, which are proving such a boon to the lanternist owing to their simple manipulation as compared with arc lamps, are attended by certain limitations, which call for special consideration in the construction of modern projection lenses. No . l170 The filament in these Lamps is, of course, concentrated as much as is possible, but the fact remains that the area of the illuminant is con- siderably larger than is the case with arc lamps, consequently, unless the objective be of excellent quality, a considerable amount of falling off of definition may be observed towards the edges of the picture on the screen. In order to meet the situation, we have produced a series of high- class Objectives, which are known as the “ Wigmore ” Anastigmat Projection Lenses. These Lenses are London made and, in addition to giving excellent definition over the whole field, pass more light than is the case with the average objective usually suppfied with Optical Lanterns designed for use with limelight or electric arc light. The “ Wigmore ” Anastigmat Lenses are made at present in two sizes only, viz., 2|in. and Sin. diameter. 1170 The “ Wigmore ” Anastigmat Projection Lenses, complete in Rack Mount, with standard 2\in. Thread for fitting to Lantern Front, focus %in., lOin., Ylin. or lAin. £8 5 0 T>ino, \6in., l^in. or 2Qin. focus ... ... £|0I0 0 l170a Ditto, in Helical Mounts, 8m. to \Ain. focus, each £7 7 0 Ditto, 16m., 18m. or 20m./ocMi ... ... £9 10 0 1171 Ditto, in Tubes only, to fit standard Tube Rack Mount, Sin. to I4in. focus ... £5 10 0 Ditto, 16m., 18m. or 20m./oc«s ... ... £7 10 0 1172 The “ Wigmore ” Large Diameter (Sin.) Projection Lens, focus up to SOin. In tubes only ... ... £|2 2 6 NEWTON & CO., 72 WIGMORE STREET, LONDON, W.l 16