Difference between revisions of "Focus (of a fixed lens)"
Jump to navigation
Jump to search
Line 1: | Line 1: | ||
'''2-2-105 | '''2-2-105 | ||
Line 7: | Line 6: | ||
Note: The term "focus" in its more general and correct sense is given in 2-1-125. | Note: The term "focus" in its more general and correct sense is given in 2-1-125. | ||
[[Image: | [[Image:Ch2_Fig16b.jpg|400px]] | ||
[[Image:Ch2_Fig18.jpg|400px]] | [[Image:Ch2_Fig18.jpg|400px]] |
Revision as of 08:56, 1 March 2009
2-2-105
The point of intersection of the axis of the lens (2-2-115) and the median horizontal plane through the belt. A ray of light emitted by a point source situated at this point is re-directed by an element of the lens into a direction normal to the axis of the lens. (Figs. 16b and 18)
Note: The term "focus" in its more general and correct sense is given in 2-1-125.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)