The dictionary of photography for the amateur and professional photographer (1897)
Wall, E. J. (Edward John), 1860-1928, Bolas, Thomas · London : Hazell, Watson & Viney · leaf 149
emitting rays which pass through the negative on slide P, and let o be the objective or projecting lens. It will be seen from this that practically very little light passing through the slide reaches the objective ; but by placing Fig. 21. a condenser between the radiant and slide it will be seen… … Fig. 22. Fig. 23. account of their great thickness they would be liable to crack, and there are other objections. It has been the custom, there- fore, to split the single lenses, and mount the two lenses with their convex surfaces nearly touching as in fig. 22. A further improvement, suggested by…
Photography
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