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Daisy Chain Flash Synch Cables.

I've been told on good authority that you can daisy chance a number of SC-28 or SC-29 to extend the range of your off camera flash work, I was wondering if you used multiple SC-29's would you get more then one focus assist beam ? Has anyone tried this, if not does anyone have more then one to give it a test ?

(not really a useful questions, more of a .. I wonder what happens when you set it up like this.. )

Craig, I'm not sure what you would want from 5 AF assist beams

Like I said it might not be pratical.. but get enough you could light somone up like a Christmas Tree...

it was more.. well if you did it, how would it work.. Each unit has that little three way switch..

(I'm obviously thinking about things too much.. going a little stirr crazy without Dawesy in the office).

not possible unless you make mods. However, unless your an octopus, this might be a handful...

wendellt posted a pic of 3 SB-800's taped together, with an SC-29 to the first, and wireless to the other 2. (wireless daisy chain).

Oz_Beachside wrote:not possible unless you make mods. However, unless your an octopus, this might be a handful...

wendellt posted a pic of 3 SB-800's taped together, with an SC-29 to the first, and wireless to the other 2. (wireless daisy chain).

Oz you may of misunderstood my original questions..

I am not mounting a flash on each.. I am just making a very long cable, with possibly working AF assit lights every metre along...

I often store the unit looped back on itself, so you can definitely connect them in this fashion, I just don't know how they react.

http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00DwXB

Up to three SC-17 cords can be combined for a total length of 4.2m coiled or 8.2m straight. I know there are more sophisticated ways of controlling remote speedlights but on a tight budget the discontinued SC-17 cord is an effective, low cost alternative.

If the 3x SC-17 can be combined i don't see why SC-29's can't be.

Hi Craig,

how about this thought:
If you just want to extend the length of the SC29 cable, then
consider cutting the cable and solder connectors onto each end of the cable so that you can plug this cable back together again.
Then get a new piece of cable and also solder the same type of connectors to the ends of that cable.
Doing that you can use the SC29 with its original length or extend its length when ever you want to.
The cable has six seperate strands of isolated wire plus a copper shield.
All sorts of cable and connectors are available from different electronic shops.

HTH,
Christian

Thanks for the suggestion Christian, and yes that will get me a longer cable cheaply, (at Strobist he uses a US extenstion cord as his lengthening middle pieces, but in that case its just flash sync and not AF assist that is being "extended".

I'm not actually after the extra length, just interested to know what happened if you do rig them up together..

Its a WHAT IF style question, rather then a.. I want to do this, does it work..

If that makes sense?

Hi Craig,

Murphies Law of Electronics and Electrics state that once you get to a certain length of cord within your "daisy chain" the flash will not actually fire. The reason is that most electrical cable has a resistance that is directly related to the length of the cable. Once you get to a certain length the actual voltage will drop to the point that no useful signal is getting to the flash and therefore it will not fire. It is for this reason that radio slaves can be a more reliable option for those instances when you need to work with flash at a distance.

As to whether all the AF illuminators will work when you have SC-29s in a Daisy Chain.... No. Only the AF illuminator on the last cord that is attached to the flash will work because it is designed to get its power off the flash unit. I will not feed other illuminators in the chain as it heads away from the flash towards the camera.

Always happy to help... Antsl !!!!!!

Alpha_7 wrote:

Oz_Beachside wrote:not possible unless you make mods. However, unless your an octopus, this might be a handful...

wendellt posted a pic of 3 SB-800's taped together, with an SC-29 to the first, and wireless to the other 2. (wireless daisy chain).

Oz you may of misunderstood my original questions..

I am not mounting a flash on each.. I am just making a very long cable, with possibly working AF assit lights every metre along...

I often store the unit looped back on itself, so you can definitely connect them in this fashion, I just don't know how they react.

whoops, yes, missunderstood.

For that, I would go wireless, either through radio triggers, or if I wanted TTL, via the onboard flash, or another master (SB800, or SU800)

Antsl wrote:Hi Craig,

Murphies Law of Electronics and Electrics state that once you get to a certain length of cord within your "daisy chain" the flash will not actually fire. The reason is that most electrical cable has a resistance that is directly related to the length of the cable. Once you get to a certain length the actual voltage will drop to the point that no useful signal is getting to the flash and therefore it will not fire. It is for this reason that radio slaves can be a more reliable option for those instances when you need to work with flash at a distance.

As to whether all the AF illuminators will work when you have SC-29s in a Daisy Chain.... No. Only the AF illuminator on the last cord that is attached to the flash will work because it is designed to get its power off the flash unit. I will not feed other illuminators in the chain as it heads away from the flash towards the camera.

Always happy to help... Antsl !!!!!!

Thanks Antsl, I realised from me engineering days there is a length limit, my research tells me about 3 SC-28s will still fire the flash at the far end. What I hadn't found which you've kindly explained is that its the flash powering the AF-assist! Thanks (Perhaps next meet we can give it a test just to prove it in pratice).

Just had a look at my SC29.
It won't work.

The power connectors from the flash to the SC29 don't make contact on the camera head of the SC29, so only the SC29 actually attached to the flash will illuminate (The power for the lamps comes from the flash battery, not the camera.)

OT. When I looked, there are a pair of contacts on the camera end of the SC29 which disengage when the head is locked to the camera. They look as though they short to the earth on the hotshoe until the unit is locked. Anyone know what they are for?[/b]