FluidKnowledge on dpreview mentions that you may also need to disable driver signing in Windows 10 to get the G1 updater and driver to work properly, as it's not signed (being written for Windows 7). The AD400Prohas Super Short recycle times ranging from 0.01-0.9s you will not need to worry about a long wait between shots making sure that those important shots are not missed and reducing overall production time. Both are 4800K which is equivalent to outside daylight. The strength of the modelling lamp really helps with focusing in low light situations and seeing what the light will do without having to do test shots. Connectivity

Some folks are reporting that you have to remove the batteries from speedlights or transmitter before attaching them to USB to get the firmware updater to recognize it. Lighting modifiers such as softboxes, barn doors, snoots and beauty dishes are also readily fitted directly to the unit or the attached mount.

Included Carry Bag

The AD400Pro is an outdoor flash with exceptionally fast recycling times and a stable output throughout the entire power range. The flash boasts a powerful lithium battery, that is capable of producing up to 390 full-power flashes on a single charge. The AD400Pro features a 2600mAh lithium-ion battery that is capable of fast recycling times of 0.01-1.0s, up to 390 flashes at full power and a fast recharge time of less than 3 hours.

When used with a Godox X2T trigger *, the AD400Pro is compatible with Canon, Nikon, Sony, Olympus/Panasonic, Fujifilm and Pentax automatic flash metering system. This allows for a more fast and efficient workflow. In summary, though, it feels like a good solid light, and it seems to have all the features that were added to the AD600 Pro in a recent firmware. The AD400Pro can produce long bursts of controlled light in Colour Mode and High-Speed Sync and has a recycling time of 1 second even when used at maximum power. The flash duration can go as low a 1/ 12340s (at 1/256, t0.1) allowing you to freeze fast moving objects such as liquid splashes or sports. When we initially set out that day to test the XPro-P trigger, we hadn’t planned to have the AD400 Pro audition for us at the same time. We had originally hoped to use the AD200, but we ended up not doing. The reasons why we didn’t use the AD200 will be explained in the XPro-P review in a few days, but it forced us to use the AD400 Pro.

Conclusion

The Godox Witstro AD400Pro All-in-One Outdoor Flash has 400ws strength power, 0.01-1s recycling time, 12 continuous flashes in 1/16 power output, 40w LED modelling lamp, 380 full power pops and stable colour temperature (which changes within +-75k over the entire power range in colour temperature mode.

The One System allows you to communicate with our GODOX flash's built-in receivers and control them all from one trigger. The 2.4GHz trigger system will give you full functionality, compatible with Canon, Nikon, Sony, Fuji, Olympus & Pentax with full control, and even high-end cameras from Hasselblad, Leica, and PhaseOne with basic control. The AD400Pro TTL Studio Flash Series Features new re-designed flash tubes with a colour consistency of 5600K +75k. The process of adjusting to TTL, Manual, or Multimode is straightforward, and it is easy to customise the settings and play around with different lighting effects – these can all be adjusted using the side control panel on both units.Master and Slave Function: AD400Pro can use with combination with Godox TTL camera flashes, TTL outdoor flashes etc. Our new price match policy guarantees you the same price as other retailers so you’re alway getting the best deal possible...

This similarity in power seems about right to me. When I compared the AD600 Pro to the AD600BM a few months, I did see about a 1/2 to 2/3 of a stop increase on the AD600 Pro when using the same modifiers. And the AD400 Pro is about 1/2 to 2/3 of a stop less powerful than the AD600 Pro. Pros The main differences are that the AD600Pro does not have the option for interchangeable adapter rings for Bowens, Profoto and Elinchrom, and obviously there’s the 200-watt power output difference between the two flash heads. This kit also includes a Bowens mount adapter making it compatible with an even greater range of light modifiers and accessories. The Godox AD400 Pro TTL Witstro Flash Head is a versatile flash unit that is designed for outdoor and location use in mind. This model offers 400Ws with 9 steps of power output which ranges from 1/1 to 1/256. It's powered 2600mAh lithium-Ion battery that offers up to 390 full-powered flashes on a single charge with a recycle time of just 0.9 seconds - Perfect for location shoots where you don't want to have to worry about battery consumption. There's also a 30W LED modelling lamp that will help you effectively manipulate your light. The unit has an integrated 2.4 GHz wireless X system with a range of 100m. This system is compatible with Godox X triggers but also fully supports Canon, Nikon, Sony, Fujifilm & Olympus TTL systems. The colour appeared consistent throughout the power levels – at least, certainly more consistent than the AD200 and AD360II – and the recycle times were very short, even when shooting high speed sync.

Pros

Get the correct exposure automatically to make worrying about settings, not an issue, ideal for those shooting in changing conditions that come from shooting outdoors and to get you to start shooting with little to no fuss. The AD400PRO 400 Pro is compatible with Canon, Nikon, Sony, Olympus, Panasonic, Fujifilm, and now Pentax’s TTL Systems, allowing the AD400PRO to seamlessly integrate into your current TTL flash system. GODOX triggers are recommended for complete control of your unit. Due to its size, the AD100 Pro is a great light to hold and maneuver as you need. Because it is so light and small, it is perfect for squeezing into tight spaces and angles to achieve the perfect lighting. It can also be simply held in your hand and moved around accordingly which isn’t possible or can be uncomfortable with bigger and heavier lights. Shot on the Pentax K1 and SMC M 35-70mm f4 lens at 1/1000 (the first three) and 1/320 (far right) at f/4, ISO200 – Lex’s photos. Edit: I probably should’ve put the power & more specific details in this bit (thanks for the reminder, Ulysses).