As far as I know, the MD-2 motor drive was not meant to be removed or attached to the Nikon F2 with a roll of partially used film in the camera. An MD-3 can. But back to the MD-2, which requires the latch key be removed from the bottom of the camera, leaving a hole for light to get in.So obviously you don't want to be attaching or removing the motor drive while standing in the sunshine. But what if you duck into a closet? A typical closet in the daytime will not be dark enough for doing things like loading 4 x 5 film jolders or developing tanks. But I would think it would be OK to take off the drive from the camera and slip the latch key back in, or add the motor, as the case may be. Opinions?