Reliable AF Assist (on-axis) with an Odin TTL trigger based Off-cam Speedlite network.

(But now there's Mitros + (Mitros Plus) !!!)

 

(And now there's the Odin II!)

 

The chance addition of Pixel's TF-321 (second generation) directly under Canon's old ST-E2 allows on-axis AF assist while an Odin TCU does its thing running an off-cam Speedlite network in either ETTL or Remotely adjusted M flash.

 

The camera's hot-shoe interface is doubled using a Godox 'Dual' TTL-C cord (as shown) though for greater applicability, my preference now would be for the 'Ishoot' brand of 'Dual' TTL cord. Usually, I would only recommend using identical twin Canon Ex Speedlites in the two female hot-shoes provided by these cords. However, departing from my own rule, I discovered by chance that the addition of Pixel's second generation TF-321 adaptor between the Canon ST-E2 and either female hot-shoe of the 'Dual' TTL cord, allows the correct simultaneous operation of both attached devices (AF assist from the ST-E2). In my hands, at least, this does not work without the addition of the TF-321 directly under the ST-E2.

 

So far, I've run this from a 7D and 20D body, AF CFns set to 2. (If you have a 'fail', double check your CFns!) I have switched positions (on the 'Dual' TTL-C cord) of the TCU and ST-E2 // TF321 combo - both setups seem to work. If somebody out there has a second gen TF-321, a 'Dual' ETTL cord (Ishoot or Godox), a Canon ST-E2 & uses Odins . . . please give this a go . . . entirely at your own risk, naturally!

 

Edit: Switch locations. On further testing, I would now use an 'Ishoot' brand 'Dual' TTL cord - slightly better fit in Canon body hot-shoes - and - I would swap the attached device positions: i.e. I would have the Odin TCU above the camera, with the ST-E2 // TF-321 combo on the bracket alongside the lens - works better all-round & esp for focus point coverage.

 

Edit: This setup works reliably from a 7D , 20D and 5DIII. Although I don't use it frequently, when I have set it up, it's never let me down within the ST-E2's range. I can now focus when it's so dark that other camera settings are tricky, requiring the top screen light or the 7D's Q screen. An apparent fail from a 20D body was actually a mal-connect between the camera's hot-shoe and the Godox 'Dual' TTL-C cord. It seems I over-tightened the lock. (There is no pin with the lock on the Godox item.) The rails on a 20D hot-shoe are also painted black - I'm not yet sure if that contributed to the problem - Canon have since reverted back to un-painted rails. If all the 6 channel hot-shoe interfaces are good, then this arrangement also works from a 20D. I'm learning more about 6 channel hot-shoe interfaces. Canon camera body hot-shoes are not identical. In this particular role and although with the 7D it seemed satisfactory, I'm finding that the Godox brand of 'Dual' TTL cord is not as reliable as the 'Ishoot' brand of 'Dual' TTL cord. In this setup, the seating of the cord in the camera's hot-shoe differs very slightly between the 2 brands. The photo confirms that there are 4 hot-shoe interfaces, totaling 48 contact surfaces - for reliable service, all 48 must keep continuity perfectly. If you have reliability issues with this setup, you know where to start looking!

 

Edit: 2-8-13: This post refers to the original hardware version 'Odin for Canon'. I updated to firmware v1.2 c August 2012. It seems that Phottix migrated to 'Odin 1.5 for Canon' some time ago, without telling anyone!

 

Edit: 18-09-13: This setup is partially redundant because Phottix have released their Mitros +! That should combine Odin style control with focus assist, flash too, in a single unit in the camera's hot-shoe. Neat, but much more expensive!

 

Edit: 10-03-16: This setup also works flawlessly from a 5DIII too. So, TF 321 directly under the ST-E2 and switch positions compared to the photo i.e. the Odin TCU is best 'on-cam' with the ST-E2 / TF 321 combo alongside on a bracket.

Done