Take full advantage of all the features on compatible flashes with the third iteration of the Canon Speedlite Transmitter ST-E3-RT. This transmitter simplifies complex lighting setups by facilitating radio-controlled, two-way wireless transmission at distances up to 98.4' among up to five groups or 15 individual Speedlites. Wireless Rear Curtain Synchronization is available for capturing light trails and creating motion blur in your images. An expansive minimum output range allows you to stop down to 1/8192 for very low-light shooting. Another useful feature is FE Memory, which allows you to lock in an E-TTL flash exposure level, even in complex multi-flash setups, and subsequently continue to use it for the same scene or subject. Eight types of custom functions and three types of personal functions are included in the design. The LCD panel and backlit controls allow for easy operation even when you're working in dimly-lit environments.

Wireless Rear Curtain Synchronization    5 Groups or 15 Speedlites, Range: 98.4'    8 Custom Functions, 3 Personal Functions    LCD Information Panel, Backlit Controls

• High-performance hot shoe contacts for reliable information transmission and operation.

• Up to five groups, or 15 individual flashes can be controlled via 1 transmitter.

• Supports E-TTL II Flash, Manual Flash, Stroboscopic, and Auto External Flash Metering.

• Dot Matrix LCD Panel displays all pertinent information simultaneously and backlit control panel for easy operation.

• Eight types of custom functions with three types of personal functions.

• High-performance hot shoe contacts for reliable information transmission and operation.

• Wireless Rear Curtain Synchronization.

• Minimum output range of 1/8192.

• Built in FE Memory so you can lock in an E-TTL flash exposure level.

Related Questions and Answers

Q: 1. Does V3 reduce the amount of dropped links to flash units? This is a significant issue with V1 and V2 transmitters.

A: With the new ST-E3-RT III the improved high-performance hot shoe contacts for reliable information transmission and operation address this issue the previous models had yes.

Q: 2. Does this work with the speed lite el-100

A: No.

Q: 3. Will this item support shooting in (camera) Manual mode when combined with a EOS 1 DX Mark III and a Speedlite EL-1 or am I limited to Program mode?

A: ***********Please send this to SLR Q&A **************

Q: 4. Is the ST-E3-RT compatible with both the EL-1 and the 600EXll-RT speedlights?

A: The Canon Speedlite Transmitter ST-E3-RT (Ver. 2) will work with both the EL-1 and the 600EX II-RT.

Q: 5. Will this work with non-RT flashes, such as the Canon 580 EX II?

A: This is only for the RT flashes.

Q: 6. Is the ST-E3-RT compatible with the Canon 5D Mk4?

A: Yes. The following unit will communicate with Canon s TTL metering system.

Q: 7. Will it work with both canon flash and Godox 400pro?

A: No. System will only communicate with canons protocol system.

Q: 8. Are there any third party strobes that work with this transmitter

A: No, the Canon Speedlite Transmitter ST-E3-RT (Ver. 2) is proprietary to Canon's system.

Q: 9. Will Canon ST-E3-RT work with Canon EL-5?

A: Yes, the Canon Speedlite Transmitter ST-E3-RT (Ver. 2) works with the Canon EL-5 speedlight.

Q: 10. I currently use the previous version of this to run my fjwestcott lights 200. Are you saying this no longer works ?

A: The ST-E3-RT II can still trigger the Westcott FJ series flash heads including the FJ200.