| 摘要 |
PURPOSE:To enable limitless focus detecting operation regardless of open F value of replacement lens, by constituting the focus detector so that the photoelectric element may be changed over automatically depending on the open F value of the replacement lens to be used. CONSTITUTION:When a lens 11B of which open F value is, for example, F2 is used, a detection lever 16 is displaced depending on the extent of protrusion L of open F value transmitting member 15, a switch 19a of a switch means 19 is held in ON state, and photoelectric elements A1, A2 are connected to a comparison operating circuit 20, so that the range finding is done only with the luminous flux from a wheel band (a). When a lens 11B OF F4 open F value is mounted, the extent of protrusion L' of open F value transmitting member 15' is larger than in the case of lens 11A, and the detection lever 16 is therefore further displaced to turn off the switch 19a, while turning on a switch 19b. As a result, photoelectric elements B1, B2 are put in operation to achieve range finding. Thus, regardless of the open F value, limitless focus detecting operation may be possible. |
