Geekoto GT-400 User manual

GT-400
USER MANUAL
Indoor Outdoor Flash Light

Introduction
Product advantage
Component name
Flash mode TTL flash mode
Flash mode M manual flash mode
Multi—Stroboscopic flash mode
Flash mode S1, S2 light control mode
Flash mode High speed synchronization
Wireless flash shooting - Wireless infrared transmission
Wireless Flash transmission - Wireless 2.4G transmission
Multi lamp lighting applications
Other applications
Specification
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—
—
—
陣 (Jin)
Catalog
01
02
03
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15
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29

1
Thank you for purchasing this speedlight.
Please read this manual carefully before using the speedlight and correct use
this speedlight on the basis of full understanding.
FOREWORD
GT-400 TTL All-in-One Outdoor Flash, GT-400 has strong power, all-in-one lithium
battery pack and great portability. When using 2.4G wireless system off camera,
GT-400 can be triggered by series flash trigger in TTL/M/Multi mode, etc. With
master & slave functions, GT-400 can also use in combination with self brand.
TTL camera flashes, TTL outdoor flashes, TTL studio flashes, etc. With this flash,
your shooting will become simpler. You can easily achieve a correct flash exposure
even in complex light-changing environments. GT-400 flash system is an GT-400
flash with LED light, wireless flash trigger, and arange of dedicated light shaping
accessories. offers studio quality light for outdoor and live shooting.
offers:
The powerful and portable GT-400 meets the demands of freelance commercial
photographers, photojournalists, wedding and beach portraiture shooters, event
and backpack photographers, photograph enthusiasts, etc.
For Your Safety
1, Never trigger the speedlight around f l a m m a b l e gas or liquid gas (such as
gasoline and solvents)! There be risk of explosion!
2, Never trigger the speedlight at close range of your eyes! Using the speedlight
directly at people or animal's eyes will damage the retinas and cause serious
visual disturbance, even blindness.
3, Only use the batteries listed in this manual!
4, Never place the batteries in high-temperature environment, such as under the
sun or in the fire.
5, Keep the speedlight and battery charger away from the water(such as the rain).
6, Note in extreme high temperature or humid environment protection flash.
7, Do not place the flash in car dashboard glove compartments, when triggered
flash, Do not place an opaque object in front of the reflection screen or above,
and no dirt is allowed on the reflective screen. Otherwise the high-energy flash
will burn reflective objects on the screen or damage screen.
8, Never open the speedlight by yourself. It have danger of high voltage ,Non-professional
personnel couldn't repair parts.
Product advantage
• Compatible wireless TTL system: Fully support Canon E-TTL II, Nikon i-TTL
and other TTL systems in self brand 2.4G wireless 陣 (Jin) system. Workable as
Slave unit in a wireless flash group.
• Dot-matrix LCD panel: with clear and convenient operation.
• Built-in 2.4G wireless transmission: with all-in-one functions and 80 meters
further transmission
• Studio quality light: up to 400Ws, GN 63 (m ISO 100) . One GT-400 can
overpower the sun.
• External battery pack: professional lithium battery pack (Lithium, 14.8V-3200mAh),
0.01-2.5s recycling and 350 full power flashes.
• Light weight and portable even with power and accessories
• Wireless control: With built-in 2.4G wireless 陣 (Jin) to achieve TTL control.
Self brand C-1 (Commander) flash trigger can also be used to wirelessly adjust
flash power level and trigger the flash. GT-400 has 3.5mm sync cord jack and
PC sync socket to achieve various sync triggering mode.
• Wide-range accessories: softbox, beauty dish, snoots, color gels, etc.
• Power adjusts from full power to 1/128 in 1/3 stop increments
• Stable color temperature at 5600±200K over the entire power range
• 1/8000s high-speed sync flash, Focus-assist beam on/off & high-speed
sync triggering
2

4
Indicator light
Body
Aluminum protection ring
Tempered glass protective film
Power switch
Handle
USB interface
Buzz tips
Component name
34
0:OFF Ⅰ:Lithium battery powered ON Ⅱ:DC power supply ON
LED
modeling light
Flash Tube
Mode button
External power
supply socket
LCD panel
Umbrella
Jack of light
Lamp holder fixed knob
Set button
Component name
Infrared receiving window
Indicator light /
Test flash
Note:Setting keys have multiple functions to be used as:
【Dimming knob】 【Encoding switch】 【The initial setting button】
Infrared receiving window
Fixation screw jack
Power supply
mode switch button
lithium battery LE-27
Modeling light button
Synchronous sockets
Handle lock
C-1 trigger (standard)
Body
Heat Vents
Heat Vents
Fuse wire

56
Special Bowens bayonet converter TR-06
Standard reflector RF-07 (buy extra)
Buy extra
GT-400 can be used with the following accessories to obtain the best results of
the shooting and the use of experience.
Bee nest Snood
Standard
lithium battery Charger Power cord Lamp cover
Reflector
Flash
Soft box
Component name Component name
Reflector
Soft box
TR-06 (buy extra)

78
Initialization is complete flash into work mode, if the battery voltage during boot
self-checking is abnormal, the interface prompts the battery voltage is too low
or too high, please replace the battery.
Ready to start
The standard battery LE-27 is installed to the battery box, turn on the power of the
corresponding supply mode (lithium battery or DC power supply), flash light to
work on battery self-check, self display flash type information battery voltage is
normal to complete the system, the initialization, the boot interface is as follows:
Battery Low Battery High
Power supply:
1,Special lithium battery LE-27(3200mmAh)(standard charging voltage 16.8V-1A)
2,External DC power supply (14.8V- 1A)(by extra)
Component name Component name
Flash Mode:
Voice turn on / off
High speed sync Icon
S2 mode
S1 mode
Manual output power
Temp &
Charging battery
Battery Charging high temperature icon Strobe frequency
Flash duration
LED mode
Close:
Dimming:
All:
Synchronization:
N: Nikon C: Canon
Wireless channel
Wireless packet
2.4G packet range A/B/C/D
Infrared instruction packet range A/B/C/D
2.4G channel range 1~16
Infrared command channel range A~D
Command mode icon
2.4G mode icon
Fixed focal length
}
}
}
}
TTL system choices
TTL:Normal
i-TTL：Nikon E-TTL：Canon
}Camera selection
LED high temperature icon
}

910
LED mode
Close
Dimming
Full power
Wireless mode selection C-1 (Commander)
Flash mode TTL flash mode—
The flash can work in a conventional mode (receiving 2.4G wireless signal) and
the Nikon Canon system wireless instruction mode (receiving infrared transmission
signal). Press the <MODE> button for three seconds to switch.
The flash have 3 modes: TTL, M, Multi. In TTL mode, the camera's mete r ing
system will be the subject of the investigation from the main reflection of the flash
lighting, so as to automatically adjust the flash output, so that the main body and
background to get a balanced exposure.
Press <MODE > mode selection button until the screen shows TTL flash into the
TTL mode, It can receive from the special remote control TTL/M/Multi, C-1 exposure
signal, participate in the exposure applicable to Canon and Nikon Camera, and the
realization of high-speed synchronization, after the curtain synchronization and FEB
surrounded by exposure, you can also receive a packet flash from the remote control
to achieve Multi, M different flash output.
Select flash mode
＊Press < MODE> mode selection button, and the three flash mode will appear on
the LCD screen in turn.The lamp can work in a conventional mode (receiving 2.4G
wireless signal) and the Nikon Canon system wireless instruction mode (receiving
infrared transmission signal). Press the <MODE> button for three seconds to switch.
The flash light as a slave unit, can support TTL, M, Multi, S1, S2 . Before using the
flash and the remote control C-1 set to the same channel and group(reference to the
remote C-1 manual).
Component name

Selection flash mode
Press 【MODE】selection button until the screen shows the M mode.
Flash mode M: manual flash mode—
11 12
Th i s mode can b e based on t h e need to
ma n u a l l y set the f l a s h output exposure
power, in the 1/128 to 1/1 power between
the 1/3 file for the incremental set of flash
output, a total of 22 adjustable (as shown below).
Remote trigger signal this flash with special remote control C-1, which can realize
the wireless funtion, 16 channels (1~16), 4 groups can be set (A, B, C, D).
LED
Close Sync Full powerl
Exposure power setting
In standby mode, rotating light knob clockwise, the exposure power is increased,
and counter clockwise the exposure power is reduced.
During the process of changing the flash output, the following table will clearly
show how the aperture value is changed, such as 1/2-0.3, 1/2 + 0.3. You can see
the change of the aperture value at the time of the increase or decrease of the
flash output. For example, the amount of flash output reduced to 1/2, 1/2-0.3 or
1/2-0.7, and then increased to more than 1/2, 1/2+0.3, 1/2+0.7, will display 1/1.
Modelling brightness
The mode can also be based on the need to set the shooting LED lamp brightness,
to achieve different lighting effects. According to <MODEL> modeling light button,
LED modeling brightness will be among the "off" / "synchronization" / "full light"
switch between.
Remote trigger signal
Display flash output
1/11/1-0.3
1/2+0.7
1/1-0.7
1/2+0.3
1/2-0.3
1/4+0.7
1/2-0.7
1/4+0.3
1/ 2 1/ 4
- - -
- - -
Flash mode Multi: stroboscopic flash—
To correctly use the mode, the camera should be setted in the manual mode. When use
the Multi mode, it can issue a series of quick flash, it can be multi flash in a picture, in order
to freeze a series of actions. In this mode, the flash output power, the number of flashes
and the frequency of flash (the number of flashes per second to HZ), as required to set.
This mode is commonly used when shooting moving objects.
Selection flash mode
Press 【MODE】 selection button until the screen display multi mode.
Exposure power setting
Standby mode rotation【settings】, the clockwise rotation of the power increases,
counter clockwise rotation power decreases. Exposure power set range 1/128~
1/4 6 total files can be adjusted.
Exposure frequency setting
Standby state press 【set button】,until to the frequency of high brightness flicker,
ro t a r y encoder switch t o adjust the frequency, clockwise rotation fre q u e n c y
increases, counter clockwise rotation frequency decreases. Frequency setting
range adjustable 1~199HZ.
LED mode
Close Dimming Full power
Using stroboscopic flash, can send a series of quick flash. It can take multiple
images of a moving object in a picture. You can set the flash frequency (the number
of flashes per second, Hz), the number of flashes and the flash output.
Reduced flash output index
Increase flash output index

Calculate shutter speed
During stroboscopic flash, the shutter remains open until flash to stop. Use the
following formula to calculate the shutter speed, and then use the camera to set.
13 14
●The highly reflective subject in dark background using stroboscopic flash
more effectively.
It is recommended to use tripod and remote control switch.
When the flash output set in 1/1 and 1/2 could not be set stroboscopic flash.
You can also use "bulb" when stroboscopic flash.
If the number of flashes to show --, the flash will flash continuously, until
the shutter or battery exhausted. As shown in the following table, the number
of flashes will be limited.
●
●
●
●
In order to prevent the flash head overheating and damage, do not perform
continuous shooting stroboscopic flash more than 10 times. After flash 10
times, let the flash cool at least 15 minutes. If you try to execute the continuous
shooting stroboscopic flash more than 10 times, For prevent the flash head
overheating, flash will automatically stop. If this happens, let the flash rest
for at least 15 minutes.
Please use as below formula to confirm the shutter speed in multi mode.
Shutter speed=Number of flash/Flash multi (HZ)shutter speed.
Relation between flash power and flash time relational table
1/128
1-40
1/64
1-20
1/32
1-12
1/16
1-8
1/8
1-4
1/4
1-2
Exposure times setting
Sta n db y m od e pre ss th e 【Set tin g but ton】t he nu mbe r hig ht li ght ( yel low
back g r o u n d and red l e t t e r ) . R o t a t e the 【Setting b u t ton】adjust the number.
Clo c k w i s e rotate the t i m e s increase and c o u n t e r clockwise rotate the times
decrease the times setting is limited by power.
The mode can also be based on the need to set the shooting LED lamp brightness,
to achieve different lighting effects. According to <MODEL> modeling light button,
LED modeling brightness will be among the "off" / "synchronization" / "full light"
switch between.
Modelling brightness
Remote trigger signal
This flash with special remote control C-1, which can realize the wireless funtion,
16 channels (1~16), 4 groups can be set (A, B, C, D).
Note:
Flash mode Multi: stroboscopic flash— Flash mode Multi: stroboscopic flash—
Flash power
Flash times

15 16
Flash mode S1, S2: Wireless optical flash light mode—
Induction mode
Press <MODE> mode selection button set to S1, S2 mode.
S1：
These 2 modes are suitable for manual flash environment Master unit every flash
is induced and synchronization trigger flash. The effect as same as wireless trigger.
To normal use of this mode. The master flash should be set to the manual flash, should
not be used with pre flash TTL flash system, also should not be used with multiple
flash on red reducing function.
S2：
Suitable for TTL flash environment, also known as the "pre flash cancellation mode",
this mode can ignore the pre flash of TTL flash, and synchronization the main flash,
so can support the main flash work in the TTL mode. If the S1/S2 mode selected
by the auxiliary lamp can not be synchronized with the main control flash, please
confirm the main control flash mode, set up the induction mode of auxiliary and
output power.
LED mode
Close Sync Full powerl
Wireless channel 1~16
Group A~D
LED mode
1, Avoid reducing the main funtion of eye lamp;
2, Avoid using modelling lamp of main lamp light.
3, Avoid the main lamp use instruction mode (Nikon) or wireless mode (Canon);
4, Avoid using ST-E2 and the master light as a flash controller.
Remote trigger signal
The flash and the special remote control can be set up the remote control trigger
and parameter change, 16 channels and 4 groups .
Flash mode S1, S2: Wireless optical flash light mode—
Close Sync Full powerl
Troubleshooting guide
When using the S1/S2 mode, avoid the following: