Do I need an On-Camera Flash to Maintain Focus Assist?

I'm considering a new approach to flash for dark wedding receptions. Instead of my current approach of either bouncing or using two flashes via infared in ETTL, I'm thinking 2-3 monolights around the perimeter bounced into the corner of the ceiling to bring up ambient controlled by Cybersyncs and main lighting by an off-camera flash in manual with some kind of modifier, also via Cybersyc.

My questions mostly have to do with focus assist and the modifier. I'm looking at some collapsible softboxes. I also have a 22" white shoot through umbrella.

I'd obvioulsy have the Cybersync transmitter in the hotshoe. With that approach, I assume there's no focus assist from the remote flash since there's no way to communciate that info? If I do, won't the modifiers block it?

Or do I not get focus assist and need to have an on-camera flash set to disabled just for the focus assist? If so, how would I mount the non-firing on-camera flash and the Cybersync transmitter?

Thanks.

The shoe-mounted flash (being used for infrared beam assist) would need to have a sync port so you can hook up the transmitter responsible for telling your lights to fire.

And no - your mono-lights will not assist you in focusing.

Another alternative is to invest in triggers that have the "pass-through" ability, such as the Cactus V5.

Flash or Ste on camera hot shoe and CST to your sync port. Or passthrough triggers like already mentioned. I would prefer mini/flex with ABs or just the flashes as remote lights so that I can control the power as well as turn them on/off from camera location using AC3.

CiM_Photography wrote in post #12288055
The shoe-mounted flash (being used for infrared beam assist) would need to have a sync port so you can hook up the transmitter responsible for telling your lights to fire.

And no - your mono-lights will not assist you in focusing.

Another alternative is to invest in triggers that have the "pass-through" ability, such as the Cactus V5.

From what I have learned/experienced, the Cactus V5 does not offer pass-through. If it does, do you mind filling me in on how to do it? This is one of my biggest gripes with the Cactus v5.

Bryan's right - I don't know what I was thinking when I wrote that...

The Cactus V5 only allows you to trigger the attached flash - no ETTL and no beam assist.

CiM_Photography wrote in post #12291940
Bryan's right - I don't know what I was thinking when I wrote that...

The Cactus V5 only allows you to trigger the attached flash - no ETTL and no beam assist.

Ok, I got really excited there for a minute. There are a lot of pros to the Cactus v5, but I have my disappointments.

No ettl passthrough
the mode dial is very easy to change, and very hard to read
I wish there was a dedicated on/off switch, mine always gets left on and the batteries die.

But functionality is amazing with them.

I never did get the whole flash the corners to bring up the entire ambient thing...

Doesn't that show up in the shots !?!? If said corner happens to be in a frame, gotta keep all said corners out of frames, gotta make sure nobody is real close to that said corner in a frame...

I need to give this a try one of these days and see for myself i guess.

Thanks, guys. I think I'm going Phottix Stratos. I'm slowly working my way towards manual flash so ETTL isn't a concern, but I feel focus assist in those dark reception halls is too important to not have. It sounds as though I get that with Stratos at a fairly reasonable price.