Really it's a pity the photographs in the mentioned
books have copyright.
The 1934 2.8/80 prototype looks like a Rolleiflex
Standard but with a large 0 size Compur shutter, the
shutter diameter almost reaches the front panel
edges,the lenses also look larger than the lenses in
the Standard, these element size are the only
difference.
The 1939 2.8/80 prototype looks like an Automat with
bright wheels, however the viewfinder hood is
different, the viewfinder hood has a glass for the
Sportsfinder like the Rollei wide, but the
Sportsfinder is more elegant in the Wide of course,
there were other 2.8A prototypes after the war on the
basis of this prototype, the special glass for the
sports finder was eliminated and only used again for
the Rollei Wide sportsfinder.-
All the best
Carlos
