New features:\n\n- 1. The set-top ETTL flash: install it on the Canon camera to achieve automatic flash photography.\n- 2. Optical signal SLAVE functions: wireless remote M mode flash (optical pulse).\n- 3. Autofocus auxiliary functions.\n- 4. Automatic zoom function, flash zoom position can be back and forth with the change of the focal length of the lens.\n- 5. Supporting the access to the Canon menu.\n\nFeatures:\n\n- Guide Number: 60 (ISO 100, 200mm)\n- Wireless Flash: Optical pulse transmission slave\n- Flash Mode: ETTL, M, Multi\n- Zoom range: 20 - 200mm (when using wide angle dispersion plate is 14mm)\n- High speed sync: 1/8000s\n- Slave flash: Optical pulse slave canon, light trigger S1/S2\n- Shutter synchronization: High speed sync, Front-curtain sync and Rear sync\n- Flash exposure compensation: Support (with an increment of 1/3 gear in +/-3 gear)\n- Bracket exposure: support\n- Flash exposure lock: support\n- Modeling flash: support\n- AF assist-focus: support\n- Manual flash: 1/128 – 1/1 (with an increment of 1/3 gear)\n- Frequency flash: 1-199Hz\n- Recycle time: Quick flash less than 2s, ordinary flash less than 3s.\n- Optical transmission distance: About 20 m\n- Optical transmission channels: 4\n- Flash groups: support for A/B/C groups\n- Power supply: 4*AA size batteries (Alkaline or Ni-MH is usable)\n- External interface: Hot-shoe, PC synchronous interface, external charging interface\n- Battery life: Flash 100-700 times\n- Measurement: 79.7 * 142.9 * 125.4 mm\n- New weight: 420g (not including batteries)\n\nQuick Guide:\n\n- Automatic flash: Set the flash to ETTL mode, can fully automatic flash photography.\n- Light trigger slave unit (optical pulse): Press button, set the MT600c to slave, there are threee choices SLAVE Canon/SLAVE S1/ SLAVE S2.\n- The set-top flash: Press [MODE] , switch to ETTL, M, RPT mode, the installed camera can be triggered flash.\n- High-speed sync: From the camera menu, set the auto FP icon turn to “on”, after set the auto FP, your camera can use any shutter speed.\n- Auto zoom: Set A Zoom, flash zoom position can be back and forth with the change of the focal length of the lens (20 – 200 mm)\n\nSpecial Explanation:\n\n- MT600C flash as a set-top use, comprehensive support ETTL function. As off-camera used, only support wireless manual mode flash, but no TTL functions.\n- All off-camera mode, SLAVE Canon/ SLAVE S1/ SLAVE S2 support high speed with step M mode flash.\n\nPrecautions about the continuous flash\n\n- To prevent degradation and damage of the flash head caused by overheating, please do not continuously flash it for more than 20 times. After 20 times, cool it at least for 10 minutes.\n- If you use it more than 20 times in a row to continue with a short interval repeated flash, the security function may be activated to limit the flash. In the restriction period, the recycling time is automatically extended. If that happens, please cool the flash for at least 15 minutes.