Abstract: A view finder mounted on a focusing plate of a reflex camera in which light coming through a taking lens of the camera is reflected upward by a mirror and an image of the object is focused on a focusing plate horizontally located above the mirror. A first mirror is provided above the focusing plate to reflect the light from the focusing plate in parallel to the optical axis of the taking lens of the camera. A second mirror is provided optically behind the first mirror to reflect the light from the first mirror at right angle upwardly or sidewardly. The second mirror is rotatable at right angle about the optical axis of the light from the first mirror to change the direction of reflection. Either the first or second mirror has a roof prism to reverse the right and left of the image reflected thereby. Behind the second mirror is located a magnifier through which the image can be viewed.

Abstract: An interchangeable lens having a shutter unit is provided with a relay shaft which is to be connected with a shutter operating mechanism in the camera body. The camera body is provided on the front face with a fixed pin and an axially movable pin which sandwich the relay shaft of the lens therebetween. The camera body is further provided with a lock pin which is connected with the axially movable pin so that the latter is retracted by the depression of the lock pin when the interchangeable lens is attached to the camera body. The lens is first attached to the camera body and then rotated until it is stopped by a stopper. When the lens is stopped, the lock pin is returned to its projected position and the axially movable pin is also returned to its projected position to hold the relay shaft between the same and the fixed pin.

Abstract: A grip removably attached to the right side of a camera body which has a film wind-up knob on the right side. The grip has a film wind-up lever which is connected with the film wind-up knob on the camera body by way of a coupling mechanism. The grip is further provided with a shutter release button which is connected with a shutter release mechanism in the camera body by means of a cable release or the like.

Abstract: A first focusing optical system including a mirror is located behind the taking lens of a single lens reflex camera for reflecting the light coming through the taking lens at an angle with respect to the optical axis thereof and forming an inverted real image of an object to be photographed on the first focal plane in reduced scale. A second focusing optical system is provided behind the first focal plane to form an erected real image of the object on a second focal plane. The erected real image is viewed through an eyepiece as a virtual image in enlarged scale. In an embodiment of the invention, a concave mirror is used as the first focusing optical system. In a preferred embodiment of the invention, the first focusing optical system behind the taking lens is moved into and out of the optical axis of the taking lens in response to operations of the camera.