Adam, with exception to the K10D, I'm almost sure that with Pentax rear curtain synchas always been set on the flash as well.
2007/10/15, Adam Maas <[EMAIL PROTECTED]>: > Godfrey DiGiorgi wrote: > > On Oct 14, 2007, at 2:47 PM, mike wilson wrote: > > > >>> For effective second curtain sync actuation, all that is required is > >>> that the camera send a trigger signal to the flash at most .004 > >>> (1/250) second before the second curtain is released for its closing > >>> run. That's the typical longest electronic flash duration of a > >>> professional studio flash. > >>> > >>> Nothing 'smart' is necessary in the flash at all. > >> Absolutely true. It used to be done mechnically from the camera body > >> with a second set of contacts interacting with the closing curtain. > >> This, of course, required the extra contacts and a switch to use them. > >> Digital flashes can obtain the information from the (robo)camera. > >> This, > >> of course, requires the programme in both units to be able to make > >> sense > >> of the photographer's desires. > >> > >> Sometimes, I feel this is where digital lets us down. > > > > I don't know what "digital" has to do with it. > > > > Since the flash trigger is 100% transistor controlled nowadays and > > under the control of the camera's shutter, itself timed > > electronically with a computer driving it, second curtain sync > > doesn't need any additional contacts in the flash mount or shutter, > > nor any other communication between the camera and flash unit. All > > the body has to do is know what shutter time is selected for an > > exposure and that first or second curtain sync is required. Then the > > body delivers the flash trigger signal at the appropriate time: > > either when the first curtain reaches fully open or prior to > > releasing the second curtain with the correct minimum lead time. The > > simplest, dumbest flash just goes "pop" when the trigger circuit is > > closed. > > > > This is *exactly* what the Sony R1 digital camera and Panasonic L1 > > digital SLR body do. They work with my Sunpak 383 and any other non- > > dedicated flash for second curtain sync beautifully. I'm mystified > > that Pentax didn't do the same and rely upon additional > > communications between flash and body to permit second curtain sync. > > > > Godfrey > > > > I think it's 'digital' communication in this case, as rear curtain sync > is one of the features only provided in Digital TTL or P-TTL modes with > Pentax. > > With Nikon the issue is straightforward, rear curtain sync is set on the > flash, and this has endured from the late 80's(when most camera/flash > settings were set on the flash, a legacy of the F4's old-fashioned > interface). > > -Adam > > -- > 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. > -- Thibault Massart aka Thibouille ---------------------- K10D,Z1,SuperA,KX,MX, P30t and KR-10x ;) ... -- 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.
