I am using my 203FE and 205FCC in manual mode using the lens C shutter instead of the focal plane shutter. I set the camera shutter speed ring to "C", set the mode to "M" and set the shutter speed using the appropriate lens setting. I am also using Winder Fs on each camera along with a release cable.

In testing the set up with the film back off, I notice that when I just quickly depress and release the cable at let's say 1 second, the lens shutter does indeed stay open for 1 second but the focal plane shutter quickly opens and closes, effectively reducing film exposure to fractions of a second. If I want to keep the film properly exposed, I need to keep my fingers depressing the cable for a time longer than the shutter speed set on the lens.

Is the the normal function of the focal plane shutter, meaning I need to keep holding the shutter release longer, or does the focal plane shutter retract once the back is put on the camera if it is set in the "C" setting?