If your receiver has a time lag, why not:

Send the sync from somewhere the user triggers (not the camera itself);

Use a receiver on each (Camera, Flash) so the lag is equal for each;

If you have to have an extra lag (such as time for a solenoid to fire to
trip the camera shutter), use a one-shot on the Flash to delay it just
enough.

I don't know how much variation, receiver to receiver, there is on the
Ming units, never used them.

  Mark

Dan Creagan wrote:
>
> I have done the photoresistor sync before and I've also used the commercial
> versions (the cheap ones).  If RF is your thing, you can try Linx
> Technologies (www.linxtechnologies.com). Their HP version will handle 50
> Kbps and that should let you send a modest preamble/trigger sequence that
> would significantly decrease the probability of false triggers and still
> sync within 1/500th.  You could make many slaves and have each triggered
> with a different preamble (switch selectable?) if you wanted to really
> control the flash setup.  Also, you could dial in delay on the slave (flash
> 1/x seconds after trigger). Some pretty creative photos could probably
> result from multiple flashes that were 1/100th apart.  I did one with an IR
> beam breaker for a 'catch the water drop in mid splash' photo.  Just used
> polaroid until I got the trigger timing right and then did the real one with
> an open shutter in a black room.
>
> You would need a hot oscillator or latency in processing would affect the
> fastest sync timing.
>
> In all, I would buy the commercial version unless you are doing this for
> fun - which is my excuse for my projects..  A commercial kit would end up
> cheaper (IMHO).  The Linx development kit is $299 - the modules are around
> $60 for a rx/tx pair.
>
> Dan
>
> PS: I am not associated with Linx, but I've recommended them a couple of
> times.  The reason is that I've settle on them as the modules for my current
> project and I am satisfied with their performance.  I have not checked out
> many of the other modules that are available - with one or two exceptions
> which obviously wouldn't fit your needs.
>
> ----- Original Message -----
> From: Douglas Burkett
> To: PICLIST@MITVMA.MIT.EDU
> Sent: Thursday, December 09, 1999 4:14 AM
> Subject: RF Interface
>
> I've read with interest the messages about RF and IR remote interfacing
> projects, I'd like to put together a remote interface that triggers a camera
> strobe based on trigger from the camera itself.  Commercial versions of this
> in RF area are in the several hundred dollar range.  I've looked at the Ming
> series and the decode time I believe would not lend itself to syncing with a
> camera.  Most camera's (35mm) sync at around the 1/60th of second speed.  I
> have shuttered lenses that sync at upto 1/500th of a second.  I have a 16F84
> that I use with a direct connection to trigger via a cable a second strobe.
> I'd like to rid myself of the cables.
>
> Long winded I see, my question is,  are there available RF or IR modules
> that would decode in time to sync at 1/500th?  I don't want to use unencoded
> modules as false trigger would be fairly expensive waste of film.
>
> Any ideas?
>
> Thanks,
> Doug

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