Canon SPEEDLITE EL-1 Advanced User's Manual page 187

9.
Check the operation.
Press the sender unit's test flash button.
Firing groups A, B, and C will fire. If it does not fire, check that it is
placed within the operation range.
10.
Take the picture.
Set the camera and take the picture in the same way as with normal
flash shooting.
Caution
To fire the 3 firing groups A, B and C together, select <
< > setting, firing group C does not fire.
If you shoot with firing group C pointing directly toward the main subject,
overexposure may result.
With certain EOS film cameras that support E-TTL autoflash, you cannot perform
wireless multiple flash shooting with a flash ratio setting.
If there is a fluorescent light or computer monitor near a receiver unit, the presence
of the light source may cause the receiver unit to malfunction and fire inadvertently.
Note
You can press the depth-of-field preview button on the camera to fire the modeling
flash ( ).
If the receiver unit's auto power off takes effect, press the sender unit's test flash
button to turn on the receiver unit.
You cannot use the test flash when operating the flash timer, etc. on the camera
end.
187
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