MAKE A MEME
View Large Image
| View Original: | OpticalGlass_003.jpg (5588x4464) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: OpticalGlass 003.jpg The large disk in the center of the photo was one of three twelve-inch planes in NBS' possession They were rated as one0tenth of a wavelength of a true plane but in equal temperature two of them showed practically no error Disks for five-inch objectives with twenty and one-half inch focal lengths were cut from squares as shown in the top of the picture Although of such short focal length to aperture both chromatic and spherical abberations were fully corrected The curves used were an adaption of hte Tuttron formula and the glass was of NBS crown and flint Also shown in the image smaller samples of NBS optical class and workmanship National Institute of Standards and Technology National Institute of Standards and Technology PD-USGov-NIST PD-USGov National Bureau of Standards National Institute of Standards and Technology Glass | ||||
