Thoughts on Trailing Curtain Sync
jsessoms002 at nc.rr.com
Sat Jul 3 10:06:42 EDT 2010
From: mike wilson
> mike wilson wrote:
>> > John Sessoms wrote:
>>> >> The K-10D and K-20D both allow you to set the on-board flash to
>>> >> trailing curtain sync. How difficult would it be for them to make the
>>> >> hot-shoe also fire on the trailing curtain when a non-dedicated
>>> >> "flash" is installed?
>>> >> E.G. like with a radio-sync transmitter or Vivitar 285HV? Dedicated
>>> >> flash like the AF-540FGZ has its own circuitry to talk to the camera
>>> >> and can be set to trailing curtain sync.
>>> >> Is this something they could do with a firmware update?
>> > Non-dedicated flashes fire when they are told to. It doesn't mstter
>> > whether that is at the beginning, the end or halfway through exposure.
>> > On the face of it, some coding telling the camera to fire any connected
>> > flash at the end of exposure would be a comparatively simple task. So
>> > simple that I must go and see if it will work already....
> OK. With KX and AF280T, it's no go. Trailing curtain seems to be a
> PTTL-only mode, as the RTF preflashes. Some illogicality there......
> There is no trailing curtain mode on the DL2.
The non-dedicated flash fires when the main hot-shoe contact triggers.
I'm asking how the camera controls when that main hot-shoe contact
triggers. Could a camera software change make it trigger the main
hot-shoe/PC contact on the trailing curtain when the on-board flash is
set to trailing curtain? Or would it require physical changes to the
wiring inside the camera?
The K10 and the K20 allow you to set the on-board flash to
trailing-curtain. The AF-500 (which worked with the *ist-D) and the
AF-540FGZ have trailing curtain sync built into the flash.
On the K10 and the K20, with the on-board flash set to trailing curtain,
the main hot-shoe pin triggers on the front curtain. Same for the K20's
Is this main pin trigger on front curtain hard-wired into the camera, or
is this something that could be changed by a firm-ware update?
More information about the PDML