Journal - Franklin Institute of the State of Pennsylvania (1826)
Franklin Institute, Philadelphia, Franklin Institute (Philadelphia, Pa.) · [Philadelphia : Franklin Institute] · leaf 487
er, through the lower part. Now you will readily see, that by unitingtwo lenses, equal to each other, L, L (Fig.35), and placing a diaphragm D betweenthem, it follows that the distortion accom-panying the lens L, with its diaphragm be-hind it, is corrected by the action of the samediaphragm, upon… … i Zentmayer—A Lecture on Lenses. 429 Unfortunately this advantage is obtained at the sacrifice of aperture,that is, of light. I mentioned before, that the negative lens has theopposite distortion of the positive lens, so that by proper combinationof lenses of suitable curves and material,…
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