Details of exhibit
- Exhibition:
- 1909 Fifty-fourth Annual Exhibition of the Royal Photographic Society of Great Britain
- Exhibit title:
- Photographic Slide Rule
- Exhibitor:
- A. Lockett
- Section:
- Scientific and Technical Photography and its Application to Processes of Reproduction
- Exhibit No.:
- 420
- Description:
- For quickly and automatically making calculations connected with photographic optics, such as finding conjugate foci, ascertaining the focus of combined lenses, estimating, measurements of objects from photographs, &c.
A typical example of its use is shown. It is desired to fine the focal length obtained by placing a positive supplementary lens of 12 in. focus in contract with an objective of 20 in. focus. The movable ruler is set against 20 and 12 respectively on the Scales A and B. The sliding arrow will then indicate the resulting focal length on the Scale C, i.e., 7½ in. - Exhibit type:
- Photographic equipment and supplies
- Process:
- [Not Listed] ()
- Award:
- none
