The question got asked quite often on the internet lately. Is it possible to mix TTL Flashes with non-TTL manual power flashes or strobes so they sync together? For example, one guy wanted to fire two SB-900s in wireless TTL mode while also triggering an Alien Bee studio strobe at the same time.
The answer is Yes. Since I have only Nikon DSLR and Nikon Speedlight flashes (D200, SB-800, and SB-600), I can only describe what’s possible for people in similar situation. For your particular Camera/Flash brands you will need to decide if this method works for you.
In full manual flash modes, simple optical slaves would work. But Nikon TTL flashes use so-called monitor pre-flashes to determine flash exposure and to communicate with remote flash units. These light pulses will confuse the optical slaves and cause pre-mature firing of the remote flashes. There are also various RF wireless triggers but most transmit only the sync signal unless you spend some hefty amount on TTL-over-RF type wireless triggers.
To make it work, we need to deliver the sync signal to the non-TTL flashes. It is easy if the camera and flash have PC sync ports. Running a PC sync cable between the two is the easiest way. This could be a hassle for many who hates wires. In that case, a cheap set of eBay trigger such as the iShoot PT-04 CN can be used. Just hook up the transmitter to the camera via PC sync cable, then connect the non-TTL flash to the receiver.
However one thing about the Nikon DSLR camera is very strange. If you are thinking about firing the TTL flashes using the built-in flash as a commander unit, forget about it. It won’t work! The reason is that there is no sync signal when the built-in flash is popped up! It has to be down. To work around this problem, you can use a SU-800 commander unit or use one of the Nikon CLS compatible flash as a commander unit. If you need all flashes off the camera, you will need to wire one Nikon CLS compatible flash via a TTL sync cord (SC-28 or SC-29) as a commander and also contributing to exposure.
What about the cameras that do not have a PC sync port, such as D40, D40x, D50, D60, D70, D70S , D80, D90, D3000, D5000? You will need to add a PC sync port to the camera. If you are brave enough, you can probably achieve this by opening up the camera and drilling a hole somewhere. But you can also try to get the so-called TF-322 Nikon i-TTL Flash Hot Shoe to PC Sync Socket Convert Adapter (available on eBay). This little device basically passes all electrical signal of the flash hotshoe through and adds a PC sync port. A regular hotshoe to PC adapter such as the Nikon AS15 Synch Terminal Adapter will not work because it takes away the hotshoe.
What does mixed TTL and non-TTL flash mode offer compared to the all-manual flash setup that can be easily accomplished using cheap eBay triggers? For people who like to use TTL, this helps them to use additional lights that are not compatible with TTL. The TTL flash should also handle mobile subjects much better because the distance between subject and lights are not constant. In those cases, the TTL flash can provide the main source of lights while the non-TTL flashes can be used for background.
Keywords: eBay Triggers, Flash Modes, Flash photography, non-TTL, PC sync, TTL, Wireless triggers