Godox TT685C User manual

GODOX PHOTO EQUIPMENT CO.LTD
TTL Camera Flash
TT685C
For Canon
Foreword
Before using this product
Please read this user manual carefully in order to ensure your safety and the proper operation of
this product. Keep for future reference.
Thank you for purchasing this product.
This TT685C camera flash applies to Canon EOS series cameras and is compatible with E-TTL II
autoflash. With this E-TTL II compatible flash, your shooting will become simpler. You can easily
achieve a correct flash exposure even in complex light-changing environments. This camera flash
features:
zGN60 (m ISO 100, @200mm). 22 steps from 1/1 to 1/128.
zFully support Canon E-TTL II camera flash. Workable as Master or Slave unit in a wireless flash
group.
zUse dot-matrix LCD panel to make clear and convenient operations.
zWith built-in 2.4GHz wireless remote system to support transmitting and receiving.
zProvided multiple functions, include HSS (up to 1/8000s), FEC, FEB, etc.
zUse optional FT-16S to adjust flash parameters & trigger the flash.
zStable consistency and color temperature with good even lighting.

zSupport with firmware upgrade.
For Your Safety
zAlways keep this product dry. Do not use in rain or in damp conditions.
zThis product contains high-voltage electronic parts. Touching the high-voltage circuit inside it
may result in electric shock. Do not disassemble. Should repairs become necessary, this
product must be sent to an authorized maintenance center.
zStop using this product if it breaks open due to extrusion, falling or strong hit. Otherwise,
electric shock may occur if you touch the electronic parts inside it.
zDo not fire the flash directly into the eyes (especially those of babies) within short distances.
Otherwise visual impairment may occur. When taking pictures for babies, keep the flash unit at
least 1 meter (3.3 feet) away from them. Using bounce flash to reduce light intensity is also
recommended.
zDo not use the flash unit in the presence of flammable gases, chemicals and other similar
materials. In certain circumstances, these materials may be sensitive to the strong light
emitting from this flash unit and fire or electromagnetic interference may result.
zDo not leave or store the flash unit in places where the ambient temperature reads over 50°C
(e.g. in automobile). Otherwise the electronic parts may be damaged.
Contents
Foreword
For Your Safety
Name of Parts
Body

Control Panel
Dot-matrix LCD Panel
What’s in the Box of TT685C?
Separately Sold Accessories
Attaching to a Camera
Power Management
Flash Mode— E-TTL Autoflash
FEC (Flash Exposure Compensation)
FEB (Flash Exposure Bracketing)
FEL: Flash Exposure Lock
High-Speed Sync
Second-Curtain Sync
Flash Mode—M: Manual Flash
Flash Mode—Multi/Stroboscopic Flash
Wireless Flash Shooting: Optic Transmission
Wireless Settings
Master Unit’s Flash OFF
Setting the Communication Channel
ETTL: Fully Automatic Wireless Flash Shooting
ETTL: Use the Wireless Shooting of Flash Ratio
M: Wireless Flash Shooting with Manual Flash
Wireless Flash Shooting: Ratio (2.4G) Transmission
Other Applications
Wireless Control Function
Sync Triggering

Modeling Flash
Auto Focus Assist Beam
Bounce Flash
Creating a Catchlight
ZOOM: Setting the Flash Coverage and Using the Wide Panel
Low Battery Indicator
C.Fn: Setting Custom Functions
Control with the Camera’s Menu Screen
Protection Function
Technical Data
Troubleshooting
Firmware Upgrade
Compatible Camera Models
Maintenance
Conventions used in this Manual
zThis manual is based on the assumption that both the camera and camera flash’s power
switches are powered on.
zReference page numbers are indicated by “p.**”.
zThe following alert symbols are used in this manual:
The Caution symbol indicates a warning to prevent shooting problem.
The Note symbol gives supplemental information.

Name of Parts
zBody
01. Catchlight Panel
02. Built-in Wide Panel
03. Flash Head
04. Optic Control Sensor
05. Focus Assist Beam
06. Wireless Control Port
07. Sync Cord Jack
08. Hotshoe
09. Dot-marix LCD Panel
10. Lock Ring
11. Battery Compartment
12. USB Port
13. Slave Flash Ready Indicator
14. External power supply Socket
zControl Panel
15 < MODE > Mode Selection Button / Lock Button
16. < > Wireless Selection Button
17. Select Dial
18. <SET > Set Button
19. ON/OFF Power Switch
20. < > Test Button / Flash Ready Indicator

21. Function Button 1
22. Function Button 2
23. Function Button 3
24. Function Button 4
zLCD Panel
E-TTL Autoflash
M Manual Flash
Multi Flash
Radio Transmission Shooting/Optic Transmission Shooting
zMaster Unit
zSlave Unit
zWhat’s in the Box of TT685C?
1. Flash unit
2. Mini stand
3. Protection case
4. Instruction manual
zSeparately Sold Accessories
zThe display will only show the settings currently applied.
zThe functions displayed above function buttons 1 to 4, such as and
, change according to settings’ status.
zWhen a button or dial is operated, the LCD panel illuminated. (Page **)


The product can be used in combination with the following accessories sold separately, so as to
achieve best photography effects:
FT-16S power & trigger control, Car charger, Mini softbox, White & Silver reflector, Honeycomb,
Color gels, Snoot, etc.
Attaching to a Camera
1. Attach the Camera Flash.
Slip the camera flash’s mounting foot into the camera’s hotshoe all the way.
2. Secure the Camera Flash.
Rotate the lock ring on the mounting foot until it locks up.
3. Detach the Camera Flash.
Rotate the lock ring on the mounting foot until it is loosened.
Power Management
Use ON/OFF Power Switch to power the flash unit on or off. Turn off if it will not be used for an
extended period of time. Setting as a master flash, it will turn the power off automatically after a
certain period (approx. 90 seconds) of idle use. Pressing the camera shutter halfway or pressing
any flash button will wake up the flash unit. Setting as a slave flash, it will enter sleep mode after a
certain period (adjustable, 60 minutes by default) of idle use. Pressing any flash button will wake it
up.

Disabling Auto Power Off function is recommended when the flash is used off camera.
(C.Fn-APO, see p.)
Slave Auto Power Off Timer is set to 60 minutes by default. Another option “30
minutes” is available. (C.Fn-Sv APOT, see p.)


This flash has three flash modes: E-TTL, Manual (M), and Multi (Stroboscopic). In E-TTL mode, the
camera and the flash will work together to calculate the correct exposure for the subject and the
background. In this mode, multiple TTL functions are available: FEC, FEB, FEL, HSS, second
curtain sync, modeling flash, control with the camera’s menu screen.
* Press <MODE> Mode Selection Button and three flash modes will display on the LCD panel one
by one with each pressing.
ETTL Mode
Press <MODE > Mode Selection Button to enter E-TTL mode. The LCD panel will display
<>.
● Press the camera release button halfway to focus. The aperture and effective flash range
will be displayed in the viewfinder.
● When the shutter button is fully pressed, the flash will fire a pre-flash that the camera will
use to calculate exposure and flash output the instant before the photo is taken.
FEC: Flash Exposure Compensation
With FEC function, this flash can adjust from -3 to +3 in 1/3rd stops. It is useful in situations where
minor adjusting of the TTL system is needed based on the environment.
Setting FEC:
1. Press Function Button 2 < >. The icon < > and flash exposure compensation
amount will be highlighted on the LCD panel.
2. Set the flash exposure compensation amount.
● Turn the Select Dial to set the amount.
● “0.3”means 1/3 step, “0.7”means 2/3 step.
● To cancel the flash exposure compensation, set the amount to “+0”.

3. Press <SET > button again to confirm the setting.
FEB: Flash Exposure Bracketing
You can take three flash shots while automatically changing the flash output for each shot from
-3 to +3 in 1/3rd stops. The camera will record three images with different exposures: one
exposed according to camera calculations, one over-exposed and another under-exposed. Over
and under exposure amount is user adjustable. This function helps get correct exposure
especially in shooting moving objects or when environmental lights are complex.
1. Press function button 3 < >. The icon < > and the exposure bracketing amount
will be highlighted on the LCD panel.
2. Set the exposure bracketing amount.
● Turn the Select Dial to set the amount.
● “0.3”means 1/3 step, “0.7”means 2/3 step.
3. Press <SET> button again to confirm the setting. Then the FEC and FEB settings are
displayed on the LCD panel.
FEL: Flash Exposure Lock
FEL can lock the correct flash exposure setting for any part of the scene.
With <ETTL> displayed on the LCD panel, press the camera’s <FEL> button. If the camera does
not have the <FEL> button, press the < > button.
1. Focus the subject.
zFEB will be cancelled after three photos are taken.
zFor best results, set the camera drive mode to “single” and ensure the flash is ready before
shooting.
zFEB can be used with FEC and FEL.
You can prevent the FEB from being cancelled automatically after three photos are taken. (C.Fn-FEB
ACL)
The FEB shooting sequence can be changed. (C.Fn-FEB)

2. Press the <FEL> button.
* Aim the subject at the center of the viewfinder and press <FEL> button.
* The camera flash will fire a preflash and the required flash output for the subject is retained
in memory.
* Each time the <FEL> button is pressed, a preflash will be fired and a new flash exposure
setting will be locked.
High-Speed Sync
High Speed Sync (FP flash) enables the flash to synchronize with all camera shutter speeds. This is
convenient when you want to use aperture priority for fill-flash portraits.
1、Press Function Button 2 < > so that < > is displayed.
2、Check that < > is displayed in the viewfinder.
zIf the subject is too far away and underexposure, the < > icon will blink in the
viewfinder. Move closer to the subject and try the FE lock again.
zIf <ETTL> is not displayed on the LCD panel, FE lock cannot be set.
zIf the subject is too small, FE lock might not be very effective.
zIf you set a shutter speed that is the same as or slower than the camera’s
maximum flash sync speed, < > will not be displayed in the viewfinder.
zWith high-speed sync, the faster the shutter speed, the shorter the effective flash
range.
zTo return to normal flash, press < > button again. Then < > will
disappear.
zMulti flash mode cannot be set in high-speed sync mode.
zOver-temperature protection may be activated after 15 consecutive high-speed
sync flashes.

Second-Curtain Sync
With a slow shutter speed, you can create a light train following the subject. The flash fires right
before the shutter closes.
Press function button 4 < > button so that < > is displayed on the LCD panel.
M: Manual Flash
The flash output is adjustable from 1/1 full power to 1/128th power in 1/3rd stop increments. To
obtain a correct flash exposure, use a hand-held flash meter to determine the required flash
output.
1. Press <MODE > button so that < > is displayed.
2. Turn the Select Dial to choose a desired flash output amount.
3. Press <SET> button again to confirm the setting.
Flash Output Range
The following table makes it easier to see how the stop changes in terms of f/stop when you
increase or decrease the flash output. For example, when you decrease the flash output to 1/2,
1/2-0.3, or 1/2-0.7, and then increase the flash output to more than 1/2, 1/2+0.3, 1/2+0.7, and 1/1
will be displayed.
Figures displayed when reducing flash output level→
1/1
1/1–0.3 1/1-0.7
1/2
1/2-0.3 1/2-0.7
1/4
…
1/2+0.7 1/2+0.3 1/4+0.7 1/4+0.3 …
←Figures displayed when increasing flash output level

Optic S1 Secondary Unit Setting
In M manual flash mode, press < S1/S2> button so that this flash can function as an optic S1
secondary flash with optic sensor. With this function, the flash will fire synchronously when
the main flash fires, the same effect as that by the use of radio triggers. This helps create
multiple lighting effects.
Optic S2 Secondary Unit Setting
Press < S1/S2> button so that this flash can also function as an optic S2 secondary flash with
optic sensor in M manual flash mode. This is useful when cameras have pre-flash function. With
this function, the flash will ignore a single “preflash” from the main flash and will only fire in
response to the second, actual flash from the main unit.
Multi: Stroboscopic Flash
With stroboscopic flash, a rapid series of flashes is fired. It can be used to capture a multiple
images of a moving subject in a single photograph.
You can set the firing frequency (number of flashes per sec. expressed as Hz), the number of
flashes, and the flash output.
1. Press <MODE> button so that <MULTI> is displayed.
2. Turn the Select Dial to choose a desired flash output.
3. Set the flash frequency and flash times.
● Press Function Button 3 < > button to select the flash times. Turn the Select Dial
to set the number.
● Press Function Button 4 < > button to select the flash times. Turn the Select Dial
to set the number.
● After you finish the setting, press <SET> button and all the settings will be displayed.
zS1 and S2 optic triggering is only available in M manual flash mode.

Calculating the Shutter Speed
During stroboscopic flash, the shutter remains open until the firing stops. Use the formula below
to calculate the shutter speed and set it with the camera.
Number of Flashes / Flash Frequency = Shutter Speed
For example, if the number of flashes is 10 and the firing frequency is 5 Hz, the shutter speed
should be at least 2 seconds.
Maximum Stroboscopic Flashes:
1 2 3 4 5 6-7 8-9
1/4 7 6 5 4 4 3 3
1/8 14 14 12 10 8 6 5
1/16 30 30 30 20 20 20 10
To avoid overheating and deteriorating the flash head, do not use stroboscopic flash more than 10
times in succession. After 10 times, allow the camera flash to rest for at least 15 minutes. If you try to
use the stroboscopic flash more than 10 times in succession, the firing might stop automatically to
protect the flash head. If this happens, allow at least 15 minutes’ rest for the camera flash.
zStroboscopic flash is most effective with a highly reflective subject against a dark background.
zUsing a tripod and a remote control is recommended.
zA flash output of 1/1 and 1/2 cannot be set for stroboscopic flash.
zStroboscopic flash can be used with“buLb”.
zIf the number of flashes is displayed as “--”, the firing will continue until the shutter closes or
the battery is exhausted. The number of flashes will be limited as shown by the following table.
Hz
FlashOutput

1/32 60 60 60 50 50 40 30
1/64 90 90 90 80 80 70 60
1/128 100 100 100 100 100 90 80
10 11 12-14 15-19 20-50 60-199
1/4 2 2 2 2 2 2
1/8 4 4 4 4 4 4
1/16 8 8 8 8 8 8
1/32 20 20 20 18 16 12
1/64 50 40 40 35 30 20
1/128 70 70 60 50 40 40
If the number of flashes is displayed as “--”, the maximum number of flashes will be as shown in
the following table regardless of the flash frequency.
Flash Output 1/4 1/8 1/16 1/32 1/64 1/128
Number of
Flashes
2 4 8 12 20 40
Wireless Flash：Optic Transmission
This product supports wireless flash application and functions as either a master
or a slave unit. As a master unit, it can control Canon speedlites e.g. 580EXII,
600EX-RT via wireless. As a slave unit, it can receive wireless signals of Canon
Hz
FlashOutput

speedlites e.g. 580EXII, 600EX-RT and commanders of Canon cameras e.g.
7D/60D/600D.
zYou can set up two to three slave groups for E-TTL II autoflash shooting. With E-TTL II
autoflash, you can easily create various lighting effects.
zAny flash settings (of flash exposure compensation, high-speed sync, FE lock, FEB, manual
flash, Multi flash) on the master unit will be automatically sent to the slave units. So the
only thing you need to do is to set the master unit to ETTL mode without any operation
for the slave units at all during the shooting.
zThis flash can work in ETTL autoflash, M manual flash, and Multi stroboscopic flash modes
when set as a master unit.
Positioning and Operation Range
1．Wireless Settings
You can switch between normal flash and wireless flash. For normal flash shooting, be sure to
set the wireless setting to OFF.
Master Unit Setting
zEven with multiple slave units, the master unit can control all of them via wireless.
zIn this user manual, “master unit” refers to the camera flash on a camera and
“slave unit” will be controlled by the master unit.

1. Press < > button so that < >and< > are displayed on the LCD panel.
Slave Unit Setting
1. Press < > button again so that < >and < > are displayed on the LCD
panel.
2. Master Unit’s Flash OFF
When the master unit is set to OFF, only the slave units will fire a flash.
1. Press Function Button 4 so that < > is displayed on the LCD panel.
2. Press Function Button 1 < > to control the ON/OFF of the master unit.
< >：The master unit flash firing is ON.
< >：The master unit flash firing is OFF.
3. Setting the Communication Channel
If there are other wireless flash systems nearby, you can change the channel IDs to prevent
signal interference. The channel IDs of the master unit and the slave unit(s) must be set to the
same.
1. Press Function Button 4 so that < > is displayed on the LCD panel.
2. Press Function Button 1 so that < > is displayed on the LCD panel. Turn the Select
Dial to choose a channel ID from 1 to 4.
3. Press the <SET> button to confirm.
4. ETTL：Fully Automatic Wireless Flash Shooting
Even if the master unit flash firing is disabled, it still fires a preflash to transmit wireless
signals.

Using Automatic Wireless Flash with a Single Slave Unit
1、Master Unit Setting
● Attach a TT685C camera flash on the camera and set it as the master Unit.
● As a master unit, TT685C can control Canon speedlites e.g. 580EXII, 600EX-RT via
wireless.
2、Slave Unit Setting
● Set the other camera flash as the wireless slave unit.
● As a slave unit, TT685C can receive wireless signals of Canon speedlites e.g. 580EXII,
600EX-RT and commanders of Canon cameras e.g. 7D/60D/600D.
3、Check the communication channel.
● If the master unit and slave unit(s) are set to a different channel, set them to the same
channel.
4、Position the camera and flashes.
● Position the camera and flashes as the picture shows.
5、Set the master unit’s flash mode to <ETTL>.
● Set the master unit’s flash mode to <ETTL>.
● For shooting, <ETTL> will automatically be set for the slave unit.
● Set the master unit flash firing as ON to fire a flash.
6、Check that the flash is ready.
● Check that the master flash ready indicator is lightened.
● When the slave flash ready indicator is ready, the AF-assist beam lighting area will blinks
at 1 second intervals.
7、Check the flash operation.
● Press the master unit’s Test Button<>。
● Then, the slave unit will fire. If not, adjust the slave unit’s angle toward the master unit and

distance from the master unit.
Using Automatic Wireless Flash with Multiple Slave Units
When stronger flash output or more convenient lighting operation is needed, increase the
number of slave units and set it as a single slave unit.
To add slave units, use the same steps as setting “automatic wireless flash with a single slave
unit”. Any flash group can be set (A/B/C).
When the number of slave units is increased and the master unit flash firing is ON, automatic
control is implemented to make all groups of flashes fire the same flash output and ensure
the total flash output up is to standard exposure.
Using Fully Automatic Wireless Flash
The FEC and other settings that set on the master unit will also be appeared on the slave unit
automatically. The slave unit does not need any operation. Use the following settings to make

The slave unit might be out of order or fire an unwanted flash due to the nearby
fluorescent lamp or computer screen.

zPress the depth-of-field preview button on the camera to fire a modeling flash.
zIf the slave unit’s auto power off function is workable, press the master unit’s test button to
power it on. Please note that test firing is unavailable during the camera’s regular metering
time.
zThe effective time of slave auto power off is changeable.
zBy making some settings, the auto AF-assist transmitter will not blink after the slave unit’s
flash ready indicator is lightened.

wireless flashes according to the same methods with normal flash shooting.
●Flash Exposure Compensation （/Page**）●High-Speed Sync （/Page**）
●Flash Exposure Bracketing（/Page**）●Manual Flash（Page**）
●Flash Exposure Lock（Page**）●Stroboscopic Flash（Page**）
About Master Unit
Use two or more master units. By preparing several cameras that with master units flash attached,
cameras can be changed in shooting while keeping the same lighting source (slave unit).
ETTL: Use the Wireless Shooting of Flash Ratio
Auto Flash Shooting with Two Slave Unit
Divide the slave units into A and B groups and balance their shooting illumination (flash ratio).
Auto control exposure to make the total output of A and B flash groups up to standard exposure.
1、Setting the flash groups of slave unit.
● Set the flash as slave unit.
● Press Function Button 3< > and choose <A> or <B>.
● Set one slave unit as <A>, the other as <B>.
2、Setting < >.
● Step 2 to Step 4 are set on the master unit.
● Press the Function Button 4 on the master unit so that < > is displayed.

The firing frequency of stroboscopic flash during the optic transmission shooting can be set from
1Hz to 199Hz.


Press Function Button 4 so that < >、<>和< > are displayed.

3、Setting <RATIO A:B>.
● Press Function Button 2 < > so that <RATIO A:B> is displayed.
4、Setting flash ratio.
● Press Function Button 3 < >.
● Turn the Select Dial to set the amount of flash ratio and press<SET> button to confirm.
5、Taking the picture.
● The slave units will flash according to the flash ratio.
Auto Flash Shooting with Three Slave Unit
1、Setting the slave group <C>.
● Use the same method of step 1 to set the slave unit of flash group<C>.
2、Setting <RATIO A:B C>.
● Use the same method of step 1 and step 3 to set the master unit as <RATIO A:B C>.
3、Setting flash exposure compensation.
● Use the same method of step 1 to set the slave unit of flash group<C>.
● Press Function Button 2 < >. Turn the Select Dial to set the amount of flash exposure
compensation and press<SET> button to confirm.
About Slave Group Control
If three slave units are all set to < > in terms of slave ID, these slave units will be controlled
as if they were one camera flash in slave group A.
slave group A