Off hand, does anyone have any knowledge of wether fully-exposed and developed negative film is more or less opaque than undeveloped film? I would be interested to know for both C-41 color and B&W film, if they happen to be different.

At a glance, the developed film which is solid black (instead of the undeveloped orange/brown/grey) *looks* like it would block more light, but I suspect this is just an illusion based on the color. Unfortunately I don't have the right equipment to test it to know for sure.

Also, am I correct in my thinking that developed but un-fixed film would be more opaque than the same film after fixing?