Flash Firing Restriction Due to Temperature Increase
Repeated use of continuous, stroboscopic, or modeling flash at short intervals may increase the temperature of the flash head, battery, and areas near the battery compartment.
Repeated flash firing gradually increases the firing interval, up to approx. 4 sec., to avoid wearing out or damaging the flash head from overheating. Continuing to fire in this state will automatically restrict flash firing.
Note that when flash firing is restricted, a high-temperature warning icon is displayed, and the flash photography firing interval is automatically set to approx. 8 or 20 sec. (levels 1 and 2, respectively).
Temperature Increase Warning
At each of the two levels, a different warning icon is displayed as the internal temperature rises. Continuing to fire after level 1 is reached changes the state to level 2.
| Display / Beeping | Level 1 (Firing Interval: Approx. 8 sec.) |
Level 2 (Firing Interval: Approx. 20 sec.) |
|---|---|---|
| Icon |  |
 |
| LCD panel illumination | Lit | Blinking |
| Beeping | With P.Fn-05 set to [0]: Warning beep | |
Modeling lamp temperature increase warning
The following warning appears when the modeling lamp becomes hot.
To clear warning, push the joystick straight in, or press the 
button.
The modeling lamp may dim or turn off if the ambient temperature around it becomes too high.
| Display | Level 1 | Level 2 | ||
|---|---|---|---|---|
| Icon |  |
|
 |
|
| When on | When off | When on | When off | |
| Brightness | When set to max. brightness: dimmed | Off | ||
Battery temperature increase warning
The following icon appears when the battery becomes hot. After this, display reverts to the same state as the temperature increase warning ().
Continuous Flash Count and Rest Time
The following table shows the estimated continuous flash count until level 1 warning display, along with the estimated rest time required until normal flash photography can be resumed.
As measured in manual flash mode according to Canon testing standards.
Using a new, fully charged Battery Pack LP-EL
1: When using the wide panel
Caution
-
Do not touch the flash head, battery, or near the battery compartment after continuous flash firing.
After repeated use of continuous flash or modeling flash at short intervals, do not touch the flash head, battery, or near the battery compartment. The flash head, battery, and area near the battery compartment may become hot, which poses a risk of burns.
Caution
- Do not open or close the battery compartment cover while flash firing is restricted. This will cancel the flash firing restriction, which is potentially very dangerous.
- The firing interval becomes longer as the flash head becomes hotter, even if no level 1 warning is displayed.
- After a level 1 warning appears, stop using the Speedlite for at least 40 min.
- Even if you stop firing after a level 1 warning appears, a level 2 warning may still be displayed.
- Flash photography in
flash mode or in high temperatures may restrict the flash count sooner than indicated in the table. - For flash count precautions, see Precautions on continuous flash firing, Stroboscopic Flash, and Modeling Flash.
- In rare cases, environmental factors such as high temperatures may prevent firing.
- The Speedlite does not issue a warning beep when P.Fn-05 is set to [1] (), even when firing is restricted.
- No warning is given by LCD panel illumination when C.Fn-22 is set to [1] (), even if the flash head becomes hot.