Abstract: A video camera combined with a recording and reproducing system having a recording and reproducing deck unit having a generally flat shape, a camera unit, a viewfinder unit, and a battery unit. As viewed from the direction perpendicular to the widest surface of the recording and reproducing deck unit, the camera unit, viewfinder unit, and battery unit are arranged so that they are set almost in the projection area of the widest surface.

Abstract: A video camera with a VTR for recording/playback of images communicates with a camera/VTR station by means of an opto-electronic link. A first opto-electronic link operates when the camera is positioned away from the camera/VTR station, and a second opto-electronic link operates when the camera is positioned on the camera/VTR station. The first opto-electronic link operates when the video camera does not record.

Abstract: A camera with a VTR communicates with a camera station by means of an opto-electronic link. A first opto-electronic link operates when the camera is positioned away from the camera station, and a second opto-electronic link operates when the camera is positioned on the camera station. The first opto-electronic link operates only when the VTR is reproducing.

Abstract: A 2,4-5-triphenylimidazole compound having the formula: ##STR1## wherein each of R.sub.1 to R.sub.5 is a hydrogen atom, a C.sub.1 -C.sub.4 alkyl group, a C.sub.1 -C.sub.4 alkoxy group, a fluorine atom, a chlorine atom, a bromine atom, a trifluoromethyl group or a trichloromethyl group, and A is a group having the formula: ##STR2## wherein R.sub.1 and R.sub.5 are as defined above. These compounds are useful as chlorine sources for photographic image-forming compositions, and as intermediates for dimers of 2,4-5-triphenylimidazoles which are useful as photochromic agents in sunglasses.