MODIFIED NODAL POINT METHOD FOR THE MEASUREMENT OF THE FOCAL LENGTH OF DIVERGENT LENSES

Authors
PRAKASH O RAM RS
Citation
O. Prakash et Rs. Ram, MODIFIED NODAL POINT METHOD FOR THE MEASUREMENT OF THE FOCAL LENGTH OF DIVERGENT LENSES, Optics and Laser Technology, 28(1), 1996, pp. 47-48
Citations number
4
Categorie Soggetti
Optics,"Physics, Applied
Journal title
Optics and Laser Technology → ACNP
ISSN journal
00303992
Volume
28
Issue
1
Year of publication
1996
Pages
47 - 48
Database
ISI
SICI code
0030-3992(1996)28:1<47:MNPMFT>2.0.ZU;2-2
Abstract
The well-known nodal point method has been employed with some modifica tion to measure the focal lengths of divergent lenses. In this modific ation, a telescope was used to locate precisely the nodal/principal po int of the lens under test, and a travelling microscope was employed t o locate precisely the focal point of the lens as well as to measure t he focal distance. The accuracy of the measurement was found to be +/- 0.5%, with the focal length of the order of about 10 cm.