Canon’s E-TTL system for exposure control of their speedlites using rapid flashes of light before the main flash is very popular and very capable. But it does have it’s limits, especially it’s use in bright outside light or over long distances. Radio signals are the answer and have already been used in the widely popular PocketWizard Plus II and MultiMAX manual flash triggers as well as several other systems such as those from Paul Buff (CyberSync) and RadioPopper (JrX).
On a couple of recent shoots I’ve run up against some of the Canon remote (off camera) E-TTL limits, started looking into the newer radio signal TTL systems and found that there are exactly two for Canon speedlites — the RadioPopper PX and the PocketWizard MiniTT1/FlexTT5. Perhaps because this approach is somewhat new, there are tremendous differences between them and some compromises to be made with either. I thought I’d summarize my findings here for those who may also be interested.
These guys were first into the game. Their approach is to capture the pre-flash light signals Canon uses to control their Speedlites remotely, translate them into radio signals, broadcast those radio signals to their receivers, decode the signals and then relay them as light flashes into the Canon Speedlite sensor.
To accomplish all that, the RadioPopper PX transmitter is connected with velco to the top of a master speedlite (or the Canon ST-E2) mounted on the camera and the receiver unit is attached to the front of the remote speedlite(s) with a special bracket that connects to the speedlite’s hot shoe. It’s important that the remote(s) not receive any of the light flashes from the master unit, so a sticker is applied over the speedlite’s sensor with a single hole to allow the receiver to flash its signals into it.
The result is that the RadioPopper PX system works exactly like Canon’s off camera control system with all its features. You end up with a long-range, light insensitive version, so there’s little to learn.
The RadioPopper options are set with an LCD display, two colored LEDs, and a pair of buttons on the unit.
- PX Receiver: $249
- PX Transmitter: $249
- Simple and reliable
- Duplicates Canon’s own system, just using radio communication
- Long (around 1,500 feet) range
- Can control the RadioPopper JrX receivers, if you already have those
- Requires an on-camera controller (Speedlite or ST-E2)
- Cannot operate as a remote camera trigger
- While the transmitter will work with the Canon 7D popup Speedlite controller, RadioPopper does not make a bracket to mount it — its a DYI project for the user
- Ends up being a bulky addition at the camera and at the Speedlite
- Some have complained that the two button interface is a little too spartan
The folks at PocketWizard have taken a different approach from RadioPopper in that they intercept the electronic signals between the camera and the on-camera flash (Canon’s E-TTL “language”), translate that into their own ControlTL (Control The Light) “language,” transmit those signals via radio to a receiver, translate ControlTL back into Canon E-TTL, and pass that to the speedlite though its hot shoe connection.
The MiniTT1 is only a transmitter and is intended for use on the camera. The FlexTT5 is a transceiver and so can work on the camera or the speedlites. Both attach via Canon’s hot shoe connections. And both are sophisticated devices that run firmware upgradable via USB connection from your computer. Many settings for that firmware are also adjusted using the USB interface and software on the host computer.
- MiniTT1 receiver: $200
- FlexTT5 transceiver:$230
- AC3 zone controller: $70
- AC5 soft RF shield: $18
- AC7 hard RF shield: $38
- Does not require an on-camera controller
- PocketWizard a well-known and established remote speedlite control company
- Expands the Canon E-TTL control set to create new features such as PocketWizard’s HyperSync which allows increased sync speeds without going all the way to Canon’s high speed sync
- Using an AC3 zone controller, you can have full control of three light zones — Canon’s E-TTL only allows that for two zones; their zone ‘C’ is only manual
- Can control the PocketWizard Plus II and MultiMAX manual speedlite triggers, if your already have those
- The FlexTT5 can be used as a remote camera trigger
- Radio Frequency (RF) interference produced by many of Canon’s speedlites (especially the 430EX, 580EX and 580EX II) greatly interferes with the range and reliability of the MiniTT1/FlexTT5 system. So much so that PocketWizard offers their AC5 and AC7 RF shields allowing greater, but not great, range for those Canon speedlites. Its surprising, you would expect that their early product testing would have exposed this. The Canon 430EX II is known to be a low RF interference unit and will work best.
- There are persistent reports on the Internet of damage caused to Canon 580 series speedlites and easily broken MiniTT1/FlexTT5 hot shoe connections. These reports are very hard to evaluate fairly, but even those well written by identified authors are frequent enough to raise a concern. PocketWizard’s reply to my email did not deny problems, but only said they were working with Canon to verify them.
- Canon only, now. A Nikon system is in the works.
In the end, its a difficult choice and will depend on many of the photographer’s personal needs. PocketWizard’s system is more compact and sophisticated but, for me, the potential damage from and to the PocketWizard components is a show stopper. And the restrictions in range for many Canon speedlites (20 feet without the RF shields, 100 feet with them, according to PocketWizard) is severe for those working at more than typical studio ranges. If I must have a system before PocketWizard improves theirs, I’ll be going with the RadioPoppers.