Abstract: A retaining device for an annular member is provided, which is connected to a supporting member including three supporting projections which are provided on the supporting member along an imaginary circle. Three elongated supporting holes are provided on the annular member and extend in radial directions therefrom, so that the supporting projections of the supporting member are fitted within the corresponding elongated supporting holes of the annular member.

Abstract: Presented is a universal adapter ring for use in interconnecting a camera of the single lens reflex type to an optical device in a manner that maintains the alignment of the optical axes of the camera and optical device and secures the two together. Sets of coaxially arranged threads are formed on the spaced faces of the ring, and a resiliently deformable spring-steel band is coaxially arranged within the ring in association with adjustable screws that may be digitally manipulated to deform the spring-steel band into tight engagement with the cylindrical eyepiece of an optical device. A centrally apertured protective shield plate is also provided extending diametrically across the adapter ring to form an abutment against which the optical device may abut surrounding the aperture to prevent the optical device from impinging on the lens of the camera, or dropping into the camera when the lens is removed and for preventing stray light from entering the camera.

Abstract: Lens barrel (12) has a shoulder (16) therein and a retaining ring to retain lens (20) within the lens barrel. A canted coil spring member (24) is engaged between the retaining ring and lens to resiliently retain the lens in place against thermal cycling, vibration and shock.