> > From: Cotty <[EMAIL PROTECTED]> > Date: 2008/01/29 Tue AM 12:13:20 GMT > To: "pentax list" <[email protected]> > Subject: Re: Success! (Was Re: ARRRRGH! K10 D and 540 flash inseparable.) > > On 28/01/08, William Robb, discombobulated, unleashed: > > >The pin that locks the thing onto the camera is the part that should be made > >shearable, if they want to prevent damage. The part that Paul was having > >trouble with can only be made of plastic for cost cutting reasons, and to > >give their repair people something to do. > > I don't understand why you need a locking pin? > > On the flash units I've used (admittedly Canon) they just have a ring > that tightens down onto the hotshoe to keep it in place. I don't > remember what mechanism the Pentax flash I used to own had. hell i can't > remember the name of the flash, the one I adapted to fire in high > ambient light on the LX.... Oh brother, brain cells depleting rapidly now....
AF280T. It has a screw-ring system to "lock" it to the camera. Except it isn't really locked, just held by friction. As the friction is created by a screw thread, there has to be a serious amount of unscrewing to really loosen the flash. Modern systems tend to be a quickthread lever type arrangement. The lever turns a thread of very high pitch that moves in 1/4 turn what took 1.5 turns in old money. Quicker on but also quicker off. One small bump of the lever and you are fully undone, because the high pitch has much less friction than the ordinary thread. Hence the locking pin, which does not withdraw until the lever is fully moved to "open", usually requiring some extra force to do so. Pretty much the same logic applies to bayonet versus screwthread lens mounting. ----------------------------------------- Email sent from www.virginmedia.com/email Virus-checked using McAfee(R) Software and scanned for spam -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
