Used Canon Speedlite Transmitter ST-E3-RT

Item Note: Transmitter Partially Links; Populates Error and Does Not Fire; The Test Button Does Not Work; May have Additional Issues; The Cosmetic Condition is Heavily Used; SOLD AS IS; FOR PARTS ONLY; FINAL SALE

SKU: US1899008 MFR: 5743B002
$15.00
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What`s in the box:

  • ** Item Note: Transmitter Partially Links; Populates Error and Does Not Fire; The Test Button Does Not Work; May have Additional Issues; The Cosmetic Condition is Heavily Used; SOLD AS IS; FOR PARTS ONLY; FINAL SALE **
  • Pouch
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Reviews about this item

Review Summary

2025-06-22T20:00:00

Rated 5 out of 5

Great reliability and features.

I am not sure how three people gave bad reviews about having link problems. I have used this and the former model and the new R model and have never had a problem. I use the flashes in nature photography often in tough environments; sometimes with up to six flashes though normally with 2 or 3. They perform with great precision and never had a problem of any type. As a professional photographer I rely on this system and can highly recommend it for all flash uses.

SNP

2025-05-12T20:00:00

Rated 1 out of 5

Not reliable and constant dropped connections

The canon radio "RT" system is completely useless. Whatever radio frequency they use is completely crowded now in 2025. You will get inconsistent connections. Their speedlites constantly loose "link" in the middle of events. This has been an issue for many years and there is still no fix.

Jhamm15

2025-04-19T20:00:00

Rated 1 out of 5

ST-E3-RT w/Canon Speedlite Is a Complete Failure.

Bought this a few years back, along with the 600EX II -RT. I didn't get a chance to use them much until recently. So far it's been terrible. I keep losing connection with them within minutes. I went online to see if this is a common issue, and BOY is it (go to message boards and YouTube and you'll see a LOT of angry photographers with the exact same problem). Worst part is Canon's 'customer service' has clearly shown that it could care less. You would think with this many dissatisfied customers Canon would genuinely address the issue, but nope. I will tell everyone I know NEVER buy a single Canon product again, nothing (I will be on social media telling my story as well). Any company that shows this kind of contempt towards it's paying customers, is NO company ANYONE should EVER do business with! I'm going with Nikon and Godox from now on.

John Y.

2025-02-20T19:00:00

Rated 3 out of 5

Drops signal

As the other reviews state it drops connection way too often. I expect better from Canon. HOWEVER that's on auto channel, if you pick one manually it works better (thus 3 stars) but it still drops it sometimes. Just did a 2 hour photo shoot and it dropped 2 times. If you don't already have canon flashes I would recommend the Godx System from B and H. Most professionals recommend it.

Dan J.

2024-12-06T19:00:00

Rated 1 out of 5

do not buy

Why are they selling this garbage? Never holds a connection, if you're lucky enough to get one at all.

fraudFinder

2024-08-15T20:00:00

Rated 1 out of 5

Unreliable

The whole flash system is unreliable. They will lose connection in a newer wifi environment. I used to rely on this system, but no more. Canon will not even acknolwedge the issues, even though the customer forum has hundreds of posts on this topic.

Dale2

2023-09-12T20:00:00

Rated 1 out of 5

Terrible

Very inconstant. If you want to look bad by constantly having to apologize to your client for switching on and off the transmitter and hoping that the light turns green and the flashes finally fire than buy this.

cp77

2023-06-15T20:00:00

Rated 2 out of 5

Radio transmission link drops VERY often.

Flash trigger will drop connection with Canon Flashes at random times. The only way to fix this is to turn everything off and restart or by resetting the link again. The system will then go down again for a few minutes or not at all and in some cases I have to reset every couple of minutes making it impossible to use. Everything works perfect when testing but almost inevitably the link will drop again while shooting. When it works it works amazing but when it doesn't it's very unreliable. I hear Canon has known about this for over 1 year and has done nothing to fix the problem. Is there a software update that can fix this issue? a recall maybe? please help.

GMoli

2023-05-08T20:00:00

Rated 1 out of 5

DON'T WASTE YOUR MONEY

These transmitters used to work flawlessly but in the past 1-2 years there have been multiple complaints that the transmitter signal is dropped by the flash and the flash will not fire unless you constantly turn the transmitter and the flash on and off. Canon has known about this problem for years and has done nothing to fix it!

photonewbie

2023-05-07T20:00:00

Rated 1 out of 5

Worthless Piece of Junk

Flash trigger will drop connection with Canon Flashes after 1 minute. The only way to fix this is to turn everything off and restart. The system will then go down again in about 1 minute. Canon has known about this for over 1 year and has done nothing to fix the problem. I would give it zero stars if I could.

PhotoNewbie

2022-01-26T07:24:39

Rated 5 out of 5

Good buy

Works great. More compact than pictures make it seem.

KEVIN L.

2022-01-11T07:18:11

Rated 5 out of 5

Great company, great customer support, great service - highly recommen,d

I purchased the Canon ST-E3-RT Speedlite Transmitter, Version 2 on a Sunday and received a package from Adorama on Monday! Wow, that is great customer service! I also bought a Canon EOS R6 from Adorama and it arrived surprisingly quickly and in great shape. The product works great with my Canon gear. I am a hobbyist and found the product easy to use....really easy! I would also like to commend Adorma for the updates about the status of my order and expected delivery as well as their commitment to post support. Great job, Adorama!

Lowell K.

2020-12-31T14:45:15

Rated 5 out of 5

Works like a charm

Well it works flawlessly with my 600ex-II’s. I bit on the pricey side but I trust canon quality so I stayed with what I know.

CLARK S.

2020-12-21T07:23:26

Rated 5 out of 5

Excellent and Reliable.

Awesome Canon transmitter. Easy to setup and never fails. Thanks Adorama!

DAVID W.

2019-12-01T07:21:58

Rated 4 out of 5

Recommended Purchase

Works very well. Have had a little problem with it losing radio connection with flashes but since running a frequency scan and finding a stronger radio channel problem hasn’t returned!

KENNY H.

2019-11-19T06:57:18

Rated 2 out of 5

Fragile plastic toy

Be very careful about the ON/LOCK/OFF switch. This tiny snap-in part can pop-off and be lost, thus disabling your ST-E3-RT and Canon does not provide a spare part. Canon repair estimate runs about 1/3 price of new transmitter. Mine must have popped off when I was putting the transmitter back in its case. Once this lever is off, the switch contact is free floating inside. Not just free to rotate, but free to slide around in any direction. So even if you try to set it using a paper clip, any movement can cause it to power off, or lock, or come back on. For the price, I would expect something more robust. Very disappointed Canon doesn't even provide the spare part. I have used the Chinese knock off with the focus assist. It was OK, but 10% of time it didn't trigger my flash. I would recommend this over the knock-off with the caveat about extra special care when operating the switch or putting the unit back in it's case. I do shoot mostly available light or with studio flash. If i had to use this a lot, I would look to switch brands to Nikon or Sony (Cameras and lenses) if they make something sturdier. My 5D mkII and 1Dx are very sturdy and reliable, my telephoto lenses were rock solid. This is unit is a fragile, throw-away, plastic toy.

Ray R.

2019-06-14T16:02:21

Rated 5 out of 5

Transmiter

Canon you did it again, great , simple and easy to work with

Keeb C.

2019-03-05T19:00:00

Rated 3 out of 5

Good, but need focus assist

Canon should quickly bring the next version and without cutting down any of the exsting features, must add focus assist also. Usually this product gets used in low light situations and this is a must feature. Also, please do not cut any features, instead add more. Otherwise Canon should not complain that the "market is declining".

PhotoLover

2019-03-05T19:00:00

Rated 3 out of 5

Good, but need focus assist

Canon should quickly bring the next version and without cutting down any of the exsting features, must add focus assist also. Usually this product gets used in low light situations and this is a must feature. Also, please do not cut any features, instead add more. Otherwise Canon should not complain that the "market is declining".

Venny

2019-01-01T19:00:00

Rated 5 out of 5

Robust connection, easy to use

I was surprised how easy it was to establish great connection between my camera and my flash. It was also so easy to do that with my three flashes at the same time. Either easy connection all on one group, or group each one on it's own group from A to C. It works without interoption every sigle time. I love the abilities it gives me. My small portable studio weights less than 30 lb and it has background stand, backgrounds, two flashes stands with umbrelas and three flahes as well my camera. Thanks to Canon's RT Wireless Flash System everything works together. I really enjoy working with Canon RT Wireless Flash System and definetely would recommend to proffeesionals and hobbysts alike.

Jack S.

2018-12-09T18:34:16

Rated 5 out of 5

Works Great!

I use the ST-E3 to fire (2) 430EX III-RT speedlights mainly in manual flash mode. I assign each speedlight to a separate "group" and am able to control output from each light separately. Nice to be able to remotely adjust light output. It pays to read the manual and set the custom functions to suite you. I prefer the orange light on the display rather than the default green which can be a little difficult to read. Like having transmitter oriented with horizontal display/controls so it doesn't stick up too high above camera hot shoe. Considered the Yongnuo alternative but decided to keep all my equipment Canon. Unit is Canon quality as expected. Have not had too many opportunities to use in actual shoots but so far so good.

Bruce T.

2018-11-25T18:02:30

Rated 5 out of 5

Great transmitter

Easy learning curve. Tons of tutorials on utube. I like how easy it is to control my flashes. Yes it is pricey.

Karen D.

2018-07-10T18:12:10

Rated 5 out of 5

C.Y. R.

Having been behind the camera for over 45 years I have made my share mistakes. When I started out as a teenager, sure the cheaper options fit better into my meager budget, if there ever was such a thing as a budget. One had to scrimp and save up for what you wanted to purchase and by the time you were able to afford it, it was already at the end of it's life cycle and something new was introduced to take its place. Although these devices do have their application, I have since learned for me, it is less costly in the long run to stay with one brand and run with it. Hey either you are a dedicated Canon shooter of a dedicated Nikon shooter. That was a choice we make when we are faced with the decision as to which system is best to fill our own specific needs. O.E.M. manufacturer's sometimes have issues with their gear performing up to claimed specs which require tweaking, how much more for third party manufacturer's trying to emulate the original product. At least when one stays with one brand, troubleshooting becomes so much easier and there is less finger pointing trying to blame other manufacturer's for causing the problem. When everything is all under one roof, the problem is more likely to get resolved and one can get on with being productive once again. In today's day and age with information sharing so readily available, did you ever notice how radio frequency devices all appear to be "proprietary" having their own "special" frequency. This often makes things complicated for devices to communicate with one another and if they do, results can be erratic and unpredictable. With optical triggers, if the trigger was not in the direct line if the flash , it simply did not fire until it was brought into range. Who knows what really is happening in cyberspace with radio devices??? If it were not for flexible store return/exchange policies, the junk draw would overflow with incompatible tools that don't work as we need them to. Now about the ST-E3-RT Speedlite Transmitter. Things could not be easier to use. It consistently fires. It is basically a 600EX-RT but without the flash head. There is also no learning curve to try and figure out how the device operates or to try and program it to emulate the flash so that they can try to communicate. It's like plug-n-play. How much simpler can you get. When time is money, the time saved is money saved. In addition, Canon devices are often often engineered to be backwards compatible, albeit like everything else, to a point. With the return of film, I can't wait to take my trusty old Canon A1 out of retirement and have some fun. I anticipate the results will be just as spectacular even if some modes of operation may not likely operate on such a vintage camera in which the technology was not invented till decades later. If only we had something like this way back then.

Chaim R.

2018-06-19T09:38:47

Rated 5 out of 5

Great Transmitter!

Great range! Syncs with the speedlite seamlessly. Light weight, easy to use. Little pricey but totally worth it.

Cole B.

2018-04-30T16:35:33

Rated 5 out of 5

st-e3-rt speedlite transmitter

The speedlite transmitter worked great so far with the430EX III-RT. I only used it twice just to check it out. I like it hope to use it more offend.

Garry W.

2018-03-08T11:31:29

Rated 5 out of 5

Sppedlite Transmitter

This transmitter is so incredibly easy to use. It is just what I needed to get my flash off of my camera and get my light source where I need it.

Sandra M.

2017-10-08T11:19:10

Rated 5 out of 5

Wanna make your life easier?

I love the Canon ST-E3-RT! I can do much more as well as get better and more fun results!

Acacia G.

2017-09-21T08:16:17

Rated 5 out of 5

A Must have for Serious Canon Photographers

This is a "Radio" transmitter for higher end Canon Speedlites. It is phenomenal! It's easy to use and can trigger multiple speedlites. You do not meed line of sight like infrared triggers. This can work anywhere where radio signals work. It's a must have for off camera flash shots.

STEVEN C.

2017-09-19T11:58:14

Rated 5 out of 5

Excellent Tool

Very happy with this purchase. Makes using a remote flash extremely easy.

Arend T.

2017-09-11T19:18:53

Rated 5 out of 5

Great transmitter for off-camera shots!

I do photostacking of flowers, and at times I need more light for my macro lens, since I shoot a lot in the morning to keep the wind down! This is THE transmitter for my Canon 600EX RT flash- they work well together! Very easy to set up and use, and lots of wonderful features!

Mitchell H.

Canon ST-E3-RT Specifications

  • Type

    Radio transmissions wireless Speedlite transmitter

  • Compatible Cameras

    Type A EOS cameras (E-TTL II/E-TTL autoflash)

  • Sync Speed

    High-Speed Sync provided (EOS-1D X and EOS 5D Mark III only)

  • Flash Exposure Confirmation

    Flash exposure confirmation lamp lights in green
    If it does not light, shooting is not performed with the standard exposure

  • AF Assist Beam

    N/A

  • Transmission System

    Radio Transmission

  • Transmission Range

    Approx. 98.4 ft. (30m)

  • Flash Ratio Control

    1:8 - 1:1 - 8:1, power 1/2-stop increments

  • Flash Coverage

    Transmission Angle: 360½ all around

  • Slave Operation Confirmation

    Green Light
    Lit: Radio Transmissions Okay

    Red Light
    Lit: Not Connected
    Blinking: Transmission Error/ Too many units (Master units + slave
    units = more than 16 units)

    Orange Light
    Lit: Sub-master transmission
    Blinking: Receiving remote release shooting, linked shooting signal

  • Slave Unit SE Mode Cancellation

    The test flash button can be pressed to test if the slave units fire or cancel the auto power off status.

  • Power Source

    AA/LRG Alkaline Batteries x2 (Ni-MH and Lithium batteries can also be used)

  • Battery Life

    Battery Life: Approx. 10 hours continuously *When using AA/LR6 alkaline batteries used (At a room temperature +23½C/73½F).

  • SE Mode

    Power off after 5 min. of idle operation

  • Dimensions (WxHxD)

    2.7 x 2.4 x 3.1" (67.4 x 61.5 x 77.4mm)

  • Weight

    3.9 oz (110g)

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2 Accessories for Canon Speedlite Transmitter ST-E3-RT

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  • Batteries & Power Supply (2)

About Canon Speedlite Transmitter ST-E3-RT

FEATURED REVIEWS

It just works!

By FarmerTed1971

My Speedlite Transmitter simply works and works so well. I'm new to Speedlites and jumped in and purchased this and three 600EX-RT's and am loving the radio function. Controlling all three flashes from the unit over great distances or hard to reach locations is a dream. Having this capability allows my creativity to not get bogged down with inadequate gear. Thanks Canon!

State of the art finally arrived!!

By lacolorstudio

Right out of the box, it performed exceptionally well. This is a long over due product that filled a gap that was provided by third party manufacturers, that tried to please everyone. This transmitter excels in the following points: 1-Controls the speedlites in both ETTL and M modes. 2-Controlls multiple flash groups, which opens the possibilities to infinite amount of combinations. 3-Eliminates the need to touch the remote flashes. 4-The most amazing mode of all is the stroboscopic, with mul...

View full Review

Canon Speedlite Transmitter ST-E3-RT is compact in size but with strong capabilities which make it almost a must-have for Speedlite 600EX-RT owners.

With the same radio-based wireless transmission abilities as a "master" 600EX-RT unit, it frees a Speedlite up for use off-camera, and can control up to fifteen flashes up to 98.4 feet (30m) off-camera and that's over a full 360½ range. The Canon ST-E3-RT has thes ame advanced LCD panel and control as the 600EX-RT, and is powered by two AA-size batteries. Unlike the Speedlite Transmitter ST-E2, the ST-E3-RT is not compatible with the existing optical-type wireless flash system, and it does not have a built-in AF-assist beam.

Compatible Flashes:
• 600EX-RT
• 430EX III-RT

Compatible Cameras with E-TTL II:
• EOS-1D X Mark II
• EOS 1D X
• EOS-1Ds Mark III
• EOS 1Ds Mark II
• EOS 1D Mark IV
• EOS 1D Mark III
• EOS 1D Mark II N
• EOS 1D Mark II
• EOS 5DS
• EOS 5DS R
• EOS 5D Mark IV
• EOS 5D Mark III
• EOS 6D
• EOS 5D Mark II
• EOS 5D
• EOS 7D Mark II
• EOS 7D
• EOS 80D
• EOS 77D
• EOS 70D
• EOS 60 D
• EOS 50D
• EOS 40D
• EOS 30D
• EOS 20D
• Rebel T7i
• Rebel T6s
• Rebel T6i
• Rebel T5i
• Rebel T4i
• Rebel SL1
• Rebel T3i
• Rebel T6
• Rebel T5
• Rebel T3
• Rebel T2i
• Rebel T1i
• Rebel XSi
• Rebel XS
• ELAN 7NE
• ELAN 7N
• Rebel T2
• EOS M5
• EOS M6
• EOS M3
• EOS M

Compatible cameras with E-TTL:
• EOS-1v
• EOS 1Ds
• EOS 1D
• EOS 10D
• EOS D60
• EOS D30
• Digital Rebel XTi
• Digital Rebel XT
• Digital Rebel
• D2000
• ELAN 7E
• ELAN 7
• ELAN IIE
• ELAN II
• Rebel Ti
• Rebel K2
• Rebel 2000
• Rebel G
• Rebel GII
• EOS IX
• EOS IX Lite.

Canon Speedlite Transmitter ST-E3-RT Features

  • Lightweight and affordable way to trigger one to 15 Speedlite 600EX-RT units forradio-based Wireless E-TTL
  • Compatible for E-TTL automatic wireless flash with nearly all EOS Digital SLRs*,with all units firing at even power, or choice of A:B or A:B C flash ratios between groups of speedlites
  • E-TTL, Manual flash, or Multi-mode manual flash possible with nearly all EOS Digital SLRs*
    * Original EOS-1D and EOS-1Ds are not compatible with Canon's radio-based wireless flash for automatic E-TTL exposure; Manual or Multi-mode flash only
  • Revolutionary new "Group" mode with EOS 5D Mark III and EOS-1D X bodies independent control of up to five groups of off-camera Speedlite 600EX-RT units
  • Original EOS-1D and EOS-1Ds are not compatible with Canon's radio-based wirelessflash for automatic E-TTL exposure; Manual or Multi-mode flash only

What's in the box:

  • Item Note: Transmitter Partially Links; Populates Error and Does Not Fire; The Test Button Does Not Work; May have Additional Issues; The Cosmetic Condition is Heavily Used; SOLD AS IS; FOR PARTS ONLY; FINAL SALE
  • Pouch