Reply To: you're not a real photographer because your camera is too small/ not full frame

[cameraclicker]

I did a couple of tests with a Bowens umbrella.  Cover on vs. cover off was worth a stop.  Moving the umbrella from where I would normally position it, to the end of the shaft caused a loss of a third of a stop.  Mileage probably varies with the brand of lamp and umbrella.

The white part alone was more reflective than I expected!  With the cover off, only a third of a stop more light goes through than is reflected back.  That’s a lot of spill!