Abstract: An image pickup apparatus in which an image of an object is converted by an image sensor into video signals to be supplied to a monitor is disclosed wherein a control circuit controls the substantial exposure of the image sensor and the monitor is inhibited from displaying the video signals when the exposure is not adequately controlled by the control circuit.

Abstract: A camera is provided with a focal length variable photo-taking optical system in which a focal length varying cam groove for varying the focal length of the phototaking optical system and a barrel sinking cam groove for stowing the optical system inside a camera body are continuously arranged. In photographing, a focal length varying action can be accomplished continuously from moving the photo-taking optical system out of the camera body. In addition to that, a lens protecting cover is arranged to be automatically openable in association with the action for moving the photo-taking optical system out of the camera body.

Abstract: A variable magnification finder including from front to rear, a first lens unit of negative power, a second lens unit of positive power and a third lens unit of positive power, these three units constituting an objective lens of positive overall power, followed by an eyepiece lens of positive power, wherein a finder image formed by the first and second units near the third lens unit is observed by the eyepiece lens, and, with the other lens units being held stationary, the second lens unit is axially moved to vary the finder magnification.

Abstract: This patent application discloses a device for protecting the photographic optical system of a camera having a first detector for detecting that the back cover of the camera is open or closed and a second detector for detecting whether or not the film is winding on the takeup spool, wherein when that the back cover is open or that the film is not winding on the spool is detected by the first and second detectors, either the rear of the photographic optical system is shut off, or the photographic optical system is moved forward, so that the rear vertex of the photographic optical system is prevented from being touched with a finger or the edge of the film leader.