Elementary treatise on physics experimental and applied for the use of colleges and schools (1890)
Ganot, A. (Adolphe), 1804-1887, Atkinson, E. (Edmund) · New York : W. Wood · leaf 548
Fig. 512. 530 On Light. [558- Spherical aberration is prejudicial to the sharpness and definition of animage. If a ground glass screen be placed exactly in the focus of a lens, the image of an ob-ject will be sharply-defined in thecentre, but indis-tinct at the edges;and, vice versa, ifthe image is… … Fig. 513 is partially obviated by placing in front of the lenses diaphragms providedwith a central aperture, called stops, which admit the rays passing near thecentre, but cut off those which pass near the edges. The image therebybecomes sharper and more distinct, though the illumination is less.…
Physics
Internet Archive · University of Connecticut Library · Public Domain Mark 1.0. Free to use for anything.
