# canon st-e3 rt and speed light 600 basic flash compensation question



## archiea (Dec 5, 2018)

Hey gang,

sorry for the basic noob-sounding question. Had a flash compensation brain fail so I figure let me hit up the group:

I shoot new Canon R (Formally on 5d3) with the remote canon st-e3-rt controlling 5 canon 600 EX-RT mark1 speedlights.

Camera is on manual, F4, 160 shutter, iso 800.. shooting musicians in a bar. Flashes are dialed in manual each, 1/8 tp 1/16 power, all with a light meter, groups A-E individually. Lens is at F4, its a f2.8 24-70.

On occasion, a solo singer goes up, I can get closer, and I'd like to switch to ether the F2 135 of f1.4 50... so in other words, keep the camera at 160, iso 800 (Since the ambient is dailed in) but the lens at f1.4 to get the DOF.

I would like to gang the speed lights down 3 stops to f1.4. I hit the +/_ on the speed light remote thinking I'm taking the various group A-E (all manually dialed in) down 3 stops and nothing! No change! 

This is what I got from the electronic manual:

_GR — GROUP MODE: DIFFERENT FLASH MODE FOR EACH GROUP
The mode is available only on EOS cameras released since 2012 (such as the EOS-1D X, EOS 5D Mark III, EOS 6D, and Rebel T4i). GR mode is best suited to advanced photographers who have experience in multiple flash lighting. You can set a different flash mode for each firing group, up to a maximum of five groups (A/B/C/D/E). The available modes include:
• ETTL / ETTL II
• Manual
• Auto external flash metering
1. Perform the initial flash setup described above.
2. Press the ST-E3-RT’s MODE button until <Gr> appears in the upper-left of the LCD panel.
3. Assign each receiver unit to a firing group (A, B, C, D, or E).
4. Set the flash mode for each firing group on the sender unit.
a. While <MENU 1> shows on the LCD, press Fn Button 3 <GR>, then turn the Select Dial to highlight a group.
b. Press Fn Button 2 <* MODE>. Each press selects a flash mode (E-TTL, M, or Ext.A> for that receiver group.
c. Repeat step b to set the flash mode for each additional group.
5. Set the flash output or flash exposure compensation amount.
a. While a firing group is selected, press Fn Button 3 <* ±> to highlight the analog scale for flash exposure compensation (E-TTL or Ext.A modes) or manual flash power (M mode).
b. Turn the Select Dial to adjust the flash exposure scale that corresponds to the flash mode, then press the Select/Set Button.
*c. If you press Fn Button 2 <* ±> when <Menu 1> is on the LCD, you can set flash exposure compensation for all firing groups (E-TTL and Ext.A only).*
d. Repeat to set the flash function of any remaining groups
e. Press Fn Button 4 to return to the shoot-ready state._

I highlighted in Red what I think my problem is: I have to be in ETTL or Ext.A only.

I'm in Manual. 

Since each flash has a discreet power setting, it breaks the heart that you can't "Gang" them together and take the group down 3 stops. I would have to individually take them down.

Again, the ambient light is dialed in to be under espoused by over a stop using the shutter and iso. I use the F stop for DOF, F4 giving me a good wide group DOF at 24mm but also good isolation ability at 70mm. Pity that when I swap to the F1.4 prime for DOF that I can't do a global adjustment.

The only thing I can think of is taking the iso down 3 stops from 800 to 100, thus reducing the camera's sensitivity but that keeps the light ratio the same. 

Any thoughts? thanks!


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## Random Orbits (Dec 5, 2018)

archiea said:


> Hey gang,
> 
> sorry for the basic noob-sounding question. Had a flash compensation brain fail so I figure let me hit up the group:
> 
> ...



Yes, because the flashes are at manual power setting, flash exposure comp won't work. I would change the ISO. It's faster than changing power settings individually on the lights.


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## archiea (Dec 6, 2018)

TY Random. its a shame that you can't gang lower or raise the flash power.


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## Random Orbits (Dec 6, 2018)

archiea said:


> TY Random. its a shame that you can't gang lower or raise the flash power.



You might want to look into ETTL. I think you might be able to ratio the lights, something like A:B, A:C, etc.


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## archiea (Dec 7, 2018)

Agreed, but if so it would "overexpose" and constantly change. I used the speed lights like "spotlights" on the singers. ETTL will always fight for the optimal exposure and blast the environment with light. I prefer pools of light that cascade to black, hence why I use Rogue Snoots on the speed lights..

For instance in the pix below, the back red spotlight in the center back is a speed light. I dial them all in to be at F4. ETTL may LOWER the back spotlight but RAISE the FG singers. I will try during the next set up. Its just a mode switch on the ST-E3-RT remote. I'm hoping to get two more speed lights to throw some Cuk-filtered dapple lights on the walls.


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## magarity (Feb 14, 2019)

First I'd just like to say that's a great creative use of your speedlites and it's given me some ideas already.
My only suggestion is have you tried putting several into the same group and just adjusted the distance to subject for each instead of adjusting the power individually? Then you could only need to change one group at one power level to affect several lights. Just a modest difference in light to subject distance will have the same change as a different power level.


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