I was browsing the Canon forums this evening and someone asked about a bug regarding the PocketWizard MiniTT1/FlexTT5 and the Einstein + PowerMC2. According to the post author, PocketWizard acknowledged that with a 5D Mark II and a TT1/TT5 on the camera, if the DoF (depth of field) preview button is pressed, the modeling lamp on the Einstein would turn on (even if the modeling lamp is off and modeling lamp control is disabled on the TT1/TT5).
I had never heard of this or ever experienced it, so I decided to immediately test it.
Result: It is true.
I have my TT1/TT5 units configured to never control the modeling lamp. When I use my Einstein and PowerMC2, I always turn them off manually (via the Einstein LCD panel).
When I put the TT1 (or TT5) on the 5D Mark II, upon depressing the DoF preview button, the modeling lamp on the Einstein went from off to “Independently Adjustable” mode at full power. Upon releasing the DoF preview button, the modeling lamp would go to about 1/128th on the scale after a few seconds. Depressing the DoF preview button would cause the modeling lamp to jump to full power.
I also tested this with the 5D Mark III and it behaves in the manner above.
Please note that this only occurs when using a ControlTL channel. If using non-ControlTL (standard) channels, the above behavior does not occur. The fact that it only occurs when on ControlTL channels makes sense, because ControlTL is supposed to ’emulate’ ETTL commands from the camera to the strobe/flash over radio.
When you use a Canon Speedlite on the hot shoe of the camera, depressing the DoF preview button actually causes the Speedlite to flash at a high frequency to simulate a modeling lamp. Thus, since ControlTL is basically wireless ETTL, it is sending that same command to activate the modeling lamp to the wireless remote strobe, in this case the Einstein.
But this behavior is actually important to be aware of.
One could call it a ‘bug’ in that it activates the modeling lamp even in cases where you configure the TT1/TT5 not to control the modeling lamp, and that when the modeling lamp turns on to full power when the DoF preview button is pressed, it doesn’t turn completely off when the DoF preview button is released. This is definitely a problem for anyone using an Einstein with a PowerMC2 on portable power (e.g. Vagabond Mini Lithium). It is quite easy to accidentally depress the DoF preview button and if you are unaware while using the Einstein and a Vagabond, you might turn on the modeling lamp inadvertently and drain the battery on the Vagabond quickly.
I think this feature should remain, but PocketWizard could add/tweak a few things to clean up the behavior.
- If the DoF preview button turns on the modeling lamp of the Einstein, the modeling lamp should turn off completely after the DoF preview button is released.
- Allow users to only use this behavior/feature when modeling lamp control is enabled on the transmitting TT1/TT5.
- Allow users to completely disable the DoF preview button from activating the modeling lamp.
In the meantime, if you use a Canon 5D series with a PocketWizard TT1/TT5 system and the Einstein+PowerMC2, be aware of this issue and take countermeasures (e.g. physically remove modeling lamps) as desired/needed/preferred.