A camera mounting assembly includes a base member or plate for holding a camera and a side member or plate. In an exemplary embodiment, lower slots on the base plate or side slots on the side plate are gripped by a vertical support's quick-release mechanism to mount the camera in a landscape or portrait orientation, respectively, the camera being generally centered and evenly balanced over the support in either case. The side member is detachably fastened to the base member, which modular construction permits separately timed purchase of the base member and side member as allowed by the user's budget and further permits breakdown of the assembly for ease of transport. The side member may be generally L-shaped with a lower arm length less than the side arm length, which also facilitates transport. Other components may be detachably added such as a hand grip facilitating freehand shooting with the camera.