----- Original Message ----- From: "Axel Belinfante" Subject: Re: Thinking of AF280T flash
> > I guess the bottom line is that "dedicated" by itself is > an empty phrase. > "dedicated" is not an absolute notion, but a relative one. > it is relative to a (family) of camera body(s). > "Dedicated" is an absolute term, and means that the flash will communicate with the camera body to set the shutter speed and aperture (in the case of programmed exposure cameras). This is by no means an empty phrase, though you probably would have needed to be around the camera industry 25 or so years ago to know what the original meaning was. A "manual" flash is a single output unit which only communicates output triggering with the camera. An "auto" flash is a variable output unit which only communicates output triggering with the camera. A "dedicated" flash communicates shutter speed and aperture setting information with the camera, and causes the camera to set the shutter speed to X-sync and sets the aperture to match the flash output range. A "TTL" flash communicates flash output with the camera for the purpose of regulating output. A "dedicated TTL" flash communicates shutter speed and aperture setting information with the camera to set the shutter speed to X-sync and sets the aperture to match the flash output range and communicates flash output with the camera for the purpose of regulating output. Recently, as cameras have thunderbirded, and morphed into lens based computer systems, the method of communication had changed, but the principles haven't changed all that much. Now you know. William Robb -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
