FEC on camera vs on transmitter vs on flash

I have a need for a shoot tonight outdoors and wish to use off camera flash for fill. I have a Canon system. All is fine except I am baffled by FEC! It seems it can be set on the camera (which works as expected) but neither changes the settings on the transmitter or flash itself) or on the transmitter or on the flash. What is the difference where this is set? I am using ETTL.

Thanks!

What Brand of transmitter and Flash?

They happen to be Yongnuo, but seems like ST-E3 and 600 EX work in the identical way. FEC can be set on any of the 3 devices and I can;t find a description of when to choose where to set it.

Thanks.

Canon recommend that you set it on the flashgun then the setting is automatically transferred to the camera, not sure if this applies with your setup.

I have been using the Canon ST-E3 RT and ST-E3 RT since first introduced in 2012. I set my parameters through the ST-E3 RT (Transmitter). FEC being one of many. There are certain parameters controlled through the transmitter that do not show up on the 600 EX-RT info screen in the Off Camera scenario. I can certainly check later on today as this may fall into the category. I will get back to you on this.

When I shoot off camera with a wireless transmitter, I use the wireless transmitter for every flash related setting.

Thanks. I would think that would only be if the flash was attached to the camera as a master, no? If remote and as a slave I woul dbe surprised. One thing I think I figured out is if as a slave, it sets only on the flash if you choose to have a different setting in a group. And then that can still be done from the transmitter. So if a transmitter is involved at all, I would think no reason to ever set on the flash. Maybe?

rebop wrote in post #19128571
...And then that can still be done from the transmitter. So if a transmitter is involved at all, I would think no reason to ever set on the flash. Maybe?

This has been my thinking. All control in one place.

Thanks so much. Exactly what I would like to know.

And if you could, if you set FEC on the camera, is it shown on the ST-E3 and / or flash?

Appreciate it.

Since I keep most things set and forget except for FEC I think I prefer to set it on the camera as easiest and most intuitive if it makes no difference between setting there or transmitter.

Worked really well last night at the shoot using FEC on cam and AE Lock. Hard to be happier.

Thanks. Any reason NOT to use what is available on the camera?

Nick5 wrote in post #19128415
I have been using the Canon ST-E3 RT and ST-E3 RT since first introduced in 2012. I set my parameters through the ST-E3 RT (Transmitter). FEC being one of many. There are certain parameters controlled through the transmitter that do not show up on the 600 EX-RT info screen in the Off Camera scenario. I can certainly check later on today as this may fall into the category. I will get back to you on this.

Yes. FEC controlled through the transmitter or ON Camera 600 EX-RT as Master, does not reflect the change on the OCF
For example
Adjusted FEC on ST-E3 RT Transmitter FEC +1.0
FEC on 600 EX-RT FEC 0

Nick5 wrote in post #19129775
Yes. FEC controlled through the transmitter or ON Camera 600 EX-RT as Master, does not reflect the change on the OCF
For example
Adjusted FEC on ST-E3 RT Transmitter FEC +1.0
FEC on 600 EX-RT FEC 0

I will disagree...when I set the FEC value on the camera (7DII), it does cause an immediate and viewable on-flash menu change in the FEC value of the flash!

And nevertheless, if your Canon flash behaves differently from my Metz flash with regard to the FEC seeting on flash, DOES alter the light output. I recently did a test because a 7DII owner could not get FEC to work.

• I adjusted FEC on camera by -2EV, 0EV, and +2EV with the flash at 0EV, and the expected change in output did occur (unlike the OP experience in that thread)
  

• Camera FEC -2EV, 0EV, and +2EV with the flash menu set to FEC 0EV is identical in result to Camera FEC -2EV, 0EV, and +2EV with the flash menu set initially to FEC +1EV
  

Thanks all. Interesting, no?

I think I shall continue to make ALL changes via Transmitter except for FEC which I will do from camera as easier todo and can do without removing my eye.

And seems like the OEM Canon gear does not gain me anything (at least in these terms) that my third party gear doesn't do.

It is exceedingly simple to take test shots at home, to verify behavior. First start with a base no-flash exposure setting which UNDERexposes the ambient light exposure, so you see only what the flash is contributing to your scene, then...

With FEC control on camera

1. Set FEC -1EV, take shot 1
   
2. Set FEC 0EV, take shot 2
   
3. Set FEC +1EV, take shot 3
   

1. Set FEC -1EV, take shot 4
   
2. Set FEC 0EV, take shot 5
   
3. Set FEC +1EV, take shot 6
   

• Shot 1 = Shot 4
  
• Shot 2 = Shot 5
  
• Shot 3 = Shot 6
  

Well, my original question was is there a difference in setting FEC in the three places it can be set. Kinda morphed over to seeing if the Canon gear responded differently in showing what FEC was set to on the three devices - especially when set from the camera or transmitter. That information might have triggered and upgrade in gear as that would be a nice feature.

SO I have tested similarly to your suggestion. And seems to work the same. Which would likely prompt the answer to the original question that do not change FEC on OCF and use either camera or transmitter as desired and deemed more convenient.

Changing on OCF might change the expected result even to the point of canceling the expected result set on camera or transmitter.

I will test one more time as I have now forgotten what shows a setting change when performed where.

Thanks for a ll the replies and food for thought.