Something wrong with my AB800's??

[SGPhoto]

Ok here is the scenario and I am hoping its just something I will need to get in order for this to work next time. But I thought the AB's would "Trigger" one another??

Setup was in a Storage Facitility with hardly any lights on:

1-AB800 Camera Left beside me @ about 4 feet high with 40 Degree Grid
1-AB800 about 8-10 feet in front of the other standing about the same height with only the reflector, so "Bare Bulb"

The only thing standing in front of the "Second AB800" was a person, so I was trying to use the second AB as a light from behind him.

Problem: Second AB800 didn't fire?

I thought the AB's were "Optical" in a sense? Or will I need to get some sort of Wireless Transmitter and 2 receivers to make this work?

Hopefully its just something in the settings, but I tried putting one of them as a Slave, I tried with the modeling light and still nothing.

As soon as I get the photo off the Card I will post one so you can see the scenario I am talking about.

Just wondering if anyone else has had this issue or not?

Thanks,

Stephen Gibson

[oldfotopro]

What are you using to trigger the first AB ? Wire, pocket wizard, etc.

Make sure you don't have a miniplug plugged into the second AB
This slave cell is disengaged whenever a miniplug is inserted into the Sync Jack

[srwatters]

One major design flaw of the original AB monolights is the placement of the optical slave sensor. I believe it's actually on the rear of the flash unit. That means it works really well for background lights, but sometimes for accent or fill positions, it just doesn't 'see' the main go off. That's the main reason for using multiple wireless triggers.

In contrast, many other pro level lights have the sensor on the top of the unit so they have more availability to see the main go off. Aside from going to multiple triggers, in a pinch you can try to reposition the strobe such that it is in front of the main light.

[oldfotopro]

your 40degree grid may be shielding the second sensor. try triggering the second light by whatever means you are using and see if the other lights fires.

[mbradley]

the 40 degree grid caused the issue by limiting the spread of the light. try putting the cord or receiver on the reflector unit and it will fire both. Scott is right about the sensor being on the rear of the unit. it requires a bigger spread of light to actually fire.

oh, this is me assuming the cord or receiver were only hooked to the unit with the 40d grid on it. lol.