Foreword
Thanks for your purchase of this ST-III c TTL wireless flash trigger. This TTL wireless flash trigger can be used with a transmitter and one or more receivers for studio flash, speedlite, and camera shutter. Featuring multi-channel triggering, stable signal transmission, and sensitive reaction, it gives photographers unparalleled flexibility and control over their strobist setups. The flash trigger applies to hotshoe-mounted Canon EOS series cameras, as well as the cameras which have PC sync sockets. With ST-III C wireless flash trigger, high speed synchronization is available for most of camera flashes in the market which support E-TTL II. The max flash synchronization speed is up to 1/8000s *.
* 1/8000s is achievable when the camera has a max camera shutter speed of 1/8000s. 1/8000s is not achievable because some models of Canon EOS cameras have a max camera shutter speed of only 1/4000s.
Warning
- Do not disassemble. Should repairs become necessary, this product must be sent to an authorized maintenance center.
- Always keep this product dry. Do not use in rain or in damp conditions.
- Keep out of reach of children.
- Do not use the flash unit in the presence of flammable gas. In certain circumstance, please pay attention to the relevant warnings.
- Do not leave or store the product if the ambient temperature reads over 50℃.
- Turn off the flash trigger immediately in the event of malfunction.
- Observe precautions when handling batteries:
- Use only batteries listed in this manual. Do not use old and new batteries or batteries of different types at the same time.
- Read and follow all warnings and instructions provided by the manufacturer.
- Batteries cannot be short-circuited or disassembled.
- Do not put batteries into a fire or apply direct heat to them.
- Do not attempt to insert batteries upside down or backwards.
- Batteries are prone to leakage when fully discharged. To avoid damage to the product, be sure to remove batteries when the product is not used for a long time or when batteries run out of charge.
- Should liquid from the batteries come into contact with skin or clothing, rinse immediately with fresh water.
Names of Parts
Transmitter
Body:
- Battery Compartment
- Micro USB Port
- PC Sync Socket
- Hot Shoe Speedlite Connection
- LCD Panel
- Hot Shoe Camera Connection
Controls:
- TEST Trigger Button (Half Press, Fully Press)
- AF Assist Beam Switch (ON/OFF)
- Power Switch (ON/OFF)
- Status Indicator Lamp (LED Red Color Lamp)
- CH/OK Channel Setting Button
- GR Group Setting Button
- Select Dial
- MODE Mode Selection Button
Receiver
Body:
- Battery Compartment
- Micro USB Port
- 2.5mm Shutter Release Port
- Hot Shoe Speedlite Connection
- LCD Panel
Controls:
- TEST Trigger Button
- Power Switch (ON/OFF)
- Status Indicator Lamp (LED Red Color Lamp)
- CH Channel Setting Button
- GR Group Setting Button
Transmitter Panel Labels:
- (A) Output Settings per Group in M Mode; FEC Settings per Group in TTL Mode
- (B) Mode Settings
- (C) Group
- (D) Currently Selected Group
- (E) Channel Settings
- (F) Low Battery Warning
- (G) GR Grouping Icon
- (H) Synchronization Delay Setting Icon
- (I) Multi Mode Icon
- (J) Single Contact Icon
- (K) Second Curtain Sync
Receiver Panel Labels:
- (A) Group Setting
- (B) Channel Setting
- (C) Low Battery Indicator
Accessories
- Remote Cable (C1, C3)
- Sync Cable
- Sync Adapter
Battery
Installing Batteries
Slide the battery compartment lid of the transmitter and receiver and insert two AA batteries (sold separately) separately.
Low Battery Indication
When the battery power (2 AA batteries <2.0V) gets low, Status Indicator Lamp blinks quickly (blink cycle=0.5s). Please replace new batteries, as low power leads to no flash or flash missing in case of long distance.
Using the Flash Trigger
1. As a Wireless Studio Flash Trigger
Mount transmitter on camera hotshoe, turn on. Connect receiver to studio flash via Sync Cable (receiver's 2.5mm Shutter Release Port to studio flash sync port), turn on studio flash. Set transmitter and receiver to the same channel. Press camera shutter; studio flash triggers simultaneously. Status Indicator Lamps on both units turn red.
2. As a Wireless Speedlite Trigger
Mount transmitter on camera hotshoe, turn on. Mount speedlite to receiver's Hot Shoe Speedlite Connection, set speedlite to M mode. Set transmitter and receiver to the same channel. Press camera shutter; speedlite triggers simultaneously. Status Indicator Lamps on both units turn red.
3. As a Wired Shutter Release
Connect receiver to camera via Remote Cable (receiver's Shutter Release Port to camera's shutter port), turn on camera. Half press
4. As a Wireless Studio Flash Trigger or Speedlite Trigger with PC Sync Socket
Connection method as per sections 1 and 2. Transmitter controls flash via PC Sync Socket input by default. Press camera shutter to trigger flash using PC Sync Socket signal. PC Sync Socket can also be set as output: long press
Setting the Transmitter
Power Switch
Slide to ON. Device is on, Status Indicator Lamp does not blink. Turn off when not in use to avoid power consumption.
Power Switch of AF Assist Beam
Slide to ON to enable AF lighting output.
Channel Setting
Short press
Mode Setting
Short press
Current Group Settings
Short press
Multi Flash Settings (Times & Frequency)
In multi flash mode (no TTL/M icon), long press
Multi Flash Settings (Output Value)
In multi flash mode, short press
Group Settings
Long press
Test Flash
Press
Modeling Lamp Control
Double-click
Setting GR Grouping Mode
Press
Automatically Enter Power Saving Mode
System enters standby after transmitter sleep mode; LCD disappears. Press any button (
C.Fn: Setting Custom Functions
Table lists custom functions (C.Fn-00 to C.Fn-09) with settings and descriptions. Icon '√' indicates support, '0' indicates not supported. Examples: C.Fn-00 Synchronization delay setting (No delay or N*100 us), C.Fn-01 Single contact mode (on/off), C.Fn-02 Zoom setting (changes with camera's zoom or specific focal lengths), C.Fn-03 PC sync socket (input/output), C.Fn-04 Second curtain sync (off/on), C.Fn-05 Minimum power output value (1/128 or 1/256), C.Fn-06 Displayed groups (03 for 3 groups, 05 for 5 groups), C.Fn-07 Beeper ON/OFF (on/off), C.Fn-08 Send the setting value forcibly (on), C.Fn-09 APP mode (on).
Setting the Receiver
Channel Setting
Short press
Group Settings
Short press
Automatically Enter Power Saving Mode
System enters standby when transmitter does. LCD disappears. Press
Selecting the Operation Method
Details button operations for Transmitter and Receiver in TTL/M Mode and Multi Mode. Covers CH/OK, GR, MODE buttons for various functions like channel settings, group settings, mode switching, modeling lamp control, and custom function access. The tables describe button actions and their corresponding functions for different modes.
Attentions
- Unable to trigger flash or camera shutter: Ensure batteries are installed correctly and Power Switch is ON. Check if transmitter and receiver are on the same channel, if hotshoe mount/connection cable is well connected, and if flash triggers are set to the correct mode.
- Camera shoots but does not focus: Check if camera/lens focus mode is set to MF; if so, set to AF.
- Signal disturbance or shooting interference: Change to a different channel.
- Operating distance limited or flash missing: Check if batteries are exhausted; replace them.
- No display or 'H' on camera viewfinder despite transmitter connection and power ON: This indicates unusual transmitter operation. Check if the flash trigger is well connected to the camera via Hot Shoe Camera Connection, then power the Transmitter on again.
Caring for Flash Trigger
- Avoid sudden drops: The device may fail after strong shocks, impacts, or excess stress.
- Keep dry: The product is not water-proof. Malfunction, rust, and corrosion may occur and go beyond repair if soaked in water or exposed to high humidity.
- Avoid sudden temperature changes: Condensation can occur. Place the transceiver in a handbag or plastic bag beforehand when moving between environments of significantly different temperatures.
- Keep away from strong magnetic field: Strong static or magnetic fields from devices like radio transmitters can cause malfunction.
Technical Data
Transmitter Specifications
| Model | ST-III C |
|---|---|
| Type | For Canon |
| Compatible Cameras | Canon EOS cameras (E-TTL II autoflash), cameras with PC sync socket |
| Built-in remote system | 2.4G Wireless Transmission |
| Modulation mode | MSK |
| Power supply | 2*AA batteries |
| Exposure Control | Manual flash, TTL autoflash, TTL Control |
| High-speed sync | Yes |
| Flash exposure compensation | Yes, ±3 stops in 1/3 stop increments |
| Flash exposure lock | Yes |
| Focus assist | Yes |
| Multi flash | Yes |
| Second curtain sync | Yes |
| Modeling flash | Yes |
| Wireless Flash | Yes |
| Wireless function | Manual open |
| Controllable slave group | In TTL mode, Ratio Off; In M mode, Flash Ratio (A:B C); Support for GR group flash (A-E); In GR grouping mode, 5 groups (A/B/C/D/E); In Ratio grouping mode, 3 groups (A/B/C) |
Receiver Specifications
| Model | ST-III C |
|---|---|
| Type | For Canon |
| Transmission range(approx.) | >100m |
| Channel | 32 |
| Others | Synchronization delay: Yes (0~10ms, unit 100us). Wireless shutter release: Receiver controls camera shooting via 2.5mm sync port. ZOOM setting: Adjust flash focal length via transmitter. LCD panel: Wide, backlight on/off. Output interface: Transmitter: PC cord (input/output). Receiver: 2.5mm sync cord (output). Firmware upgrade: Micro USB port. Memory function: Settings stored for 2 seconds after last operation, recover after restart. |
| Dimension/Weight for Transmitter | 72x75x52(mm)/100g |
| Dimension/Weight for Receiver | 70x65x47(mm)/70g |
Compatible Camera Models
Canon EOS SLR Digital Cameras: 1Dx Mark II, 1Dx, 5Ds/5Dsr, 5D Mark IV, 5D Mark III, 5D Mark II, 5D, 7D Mark II, 6D, 7D, 80D, 77D, 70D, 60D, 50D, 40D, 30D, 750D/760D, 100D, 800D, 700D, 650D, 600D, 550D, 500D, 450D, 400D DIGITAL (EOS Kiss Digital X), 350D DIGITAL, 1300D (Rebel T6), 1200D, 1100D, 1000D, M6, M5, M3.
