The new flash trigger offers automatic exposure metering TTL without the need of a line of sight between camera and flashes. Infrared bases systems like ST-E2 often suffer from being hidden inside soft boxes or behind bounders which are no problem for radio based systems. Typically radio triggers offer a maximum range of up to 100m under best circumstances.
The YN-622 is much bigger than the manual trigger RF-603 and nearly the same dimensions as the Pixel King. This allows the use of widely used AA batteries and comfortable buttons.
It supports TTL, manual flash mode, 7 channels and 3 groups, high speed sync (HSS) up to 1/8000s, automatic zoom, exposure compensation, AF assist beam, PC sync and a lot more features.
Apparently the radio trigger offers a function called hyper-sync. This allows shorter sync speeds even with studio flashes or other manual flashes. Compatible to all flashes by Yongnuo and Canon's EX II flashes.

Features:

• Compatible flash mode: E-TTL II/Manual/Multi
• Compatible Shutter sync: 1st curtain, 2nd curtain, High speed sync  (HSS/FP) Max 1/8000s
• Control remote speedlites using camera's build-in flash menu
• PC port can output 1st/2nd/HSS signal to trigger studio flash
• Flash Exposure Compensation (FEC)
• Flash Exposure Bracketing (FEB)
• Flash Exposure Lock (FEL)
• Flash zooming (auto,manual)
• Modeling Flash
• E-TTL group ratio (ALL/A:B/A:B C)
• Manual/Multi Group (ALL/A:B/A:B:C)
• Live view triggering
• Focus Assist Lamp
• High-speed continuous shooting trigger
• Speedlites on hot-shoe of transmitter supports ETTL
• Compatible with ALL YongNuo/Canon EXII series speedlites
• Settings saved automatically
• Single-contact camera & speedlite triggering

Compatibility:

• This Canon EOS cameras offer in camera flash control with Yongnuo YN622C:
• 1D Mark III, 1D Mark IV, 1Ds Mark III
• 5D Mark II, 5D Mark III
• 7D
• 40D, 50D, 60D
• 450D, 500D, 550D, 600D, 650D
• 1000D, 1100D
• The following flashes will support this wireless remote control through camera menu”:
• Canon 600EX, 600EX-RT, 580EX II, 430EX II, 320EX, 270EX II
• YongNuo YN-565EX, YN468, YN468 II, YN467, YN467 II, YN465

Please note:

• If you use the Canon Speedlite 430EX or 580EX (not marked II) or an older camera without the Flash Control menu then you will have to make settings by hand. Older cameras that don’t have the same Flash Control menu include the original 5D, 10D, 20D, 30D, 300D, 350D, 1D and 1D Mark II.

Package Includes:

• Pair of YN-622 Transceivers
• User Manual
• Retail Packaging