Your probably right Scott, however from the post I doubt Source3 would be refering to something like the Strand Patt 102 effects projector or similar, as the focusing lenses don't 'flip flop' as sugested. rather they slide on two rails protruding from the lamp. If this is what you were refering too?
From the pic that was posted, it is difficult to determine if the references was to a Fresnel or a profile.
Come to thing about it I last seen a Patt 102 used almost 50 years ago at the Goldersgreen Hippodrome. They were developed during the advent of rock 'n roll & were usualy well & truly cream crackered in a very short order, because of the open lens design & with commercial usage.
Also with fresnel beam masking this is another situation where local terms tend to differ.
Beam masking be it from a shutter or barndoor on a profile, flood or fresnel is reffered to as masking & shaping the beam, including light ray scatter masked by a snoot or whatever.
Upon rereading the initial post in question, I now realise I brushed over the term 'throw'. Being more concerned with the 'B' device question, thanks for picking up on that, of course this would have made a difference to my reply, but for that 'B' word?
G'donya!
