Jim Heine Photography – Lehigh Valley, Philadelphia, and Destination Wedding & Documentary Portrait Photographer » upbeat, modern, creative photojournalism wedding photographer and documentary day in the life family photography

Canon 600EX-RT Radio Flash Review

Disclaimer: This review is intended for photographers and photography gear nerds.  If you’re looking for beautiful wedding or engagement photos, continue down the blog.:)


Radio trigger technology for flash just came into being a few short years ago and really revolutionized the photography industry.  Before then, most wedding photographers kept their flashes on their cameras or had a corded one light system.   Radio freed us of the cords and allowed us to use flashes quickly off-camera in all conditions.

Up to now I have used most of the popular radio trigger technologies extensively, including PocketWizard (Plus system), RadioPoppers (PX and JrX), and CyberSyncs.  They all have their pros and cons and applications that each excels at.  There has been one consistent problem across the board for all the triggers – they have times when they’re unreliable.  No, it’s not all the time, but sometimes the triggers just don’t work or work sporadically.  Often times the problem results from a flaky cord, connection, or interference.   Problems like these are notoriously hard to troubleshoot.  A flash might work every other shot or quit working after 5 shots.  You just never know.

Last year I started to get fed up.  It is extremely embarrassing when you’re in front of a client and your equipment malfunctions or works inconsistently.  This is especially true when you’re on an extremely tight schedule and under pressure, such as at a wedding.  There’s nothing worse than 15+ anxious bridal party members waiting for you to trouble-shoot your equipment.

So last year I switched to using Einstein flashes, Vagabond Minis, Cybersyncs, and the CyberCommander.  The Einsteins worked much more reliably, I think primarily due to less cords.  The Einsteins have a transmitter that simply plugs directly into the unit.  One less thing to go wrong.  The Einstein system is not perfect, but it’s better than any system I’ve used.  They’re a bit heavy, but I have all the features I want, including plenty of flash power/range and remote power control.

Enter Canon with the 600EX-RT.  When Canon first announced the new flash system, I had a “meh” response.  They were expensive and didn’t offer much in the way of upgrades over the 580EX flashes.  I ordered one 600EX-RT, just out of curiosity from a retailer with a very good return policy.  After minutes of getting the flash in my hands, I got two more.  I was quite excited by the all-in-one nature of the flash.  No more separate radio triggers, no more faulty cords, no more troubleshooting connections.  The best thing going for the 600EX-RT is that it should be a very reliable and foolproof system to use.

New Features

So, it’s maybe a little disappointing that the 600EX flash doesn’t have much in the way of new functional features.  The only real upgrade is to the zoom.  It now goes from 20mm-200mm compared to 24mm-105mm on the 580EXII.  A nice upgrade, but it won’t make a huge difference for most photographers.  Power output and recycle time is identical to the 580EXII.  The 600EX-RT is slightly taller than the 580EXII, but they’re not far apart.

The flash does have some other improvements, however.  One huge difference is the usability of the menu system…and you’ll need it to utilize all the neat features of the flash.  Every other professional Canon flash before the 600EX had an absolutely atrocious menu system.  Previously you had to hold in buttons to get to certain features and had to cycle through multiple options before you got to the setting you wanted.  One key feature I enjoyed on the 5d Mark II was that it added a menu option in camera to adjust flash settings.  Well now it’s equally easy to use the actual flash menu to change settings.

Now we have a MODE button that cycles through the different modes – ETTL, Manual, Group, Multiple, ExtA, ExtM.  There is also a wireless mode button that cycles between No Wireless, Radio Master, Radio Slave, and Optical.  On the LCD we see up to four menu options on the bottom.  There are four corresponding buttons for those options.  It’s not perfect, but it’s fairly intuitive.

There’s also a gel holder.  Hmm…  seems like a huge gimmick.  I’ll get into this later.

The biggest addition is the radio trigger system.  We’ll be focusing on this and its features.

Radio Modes

The reason to get this flash is the radio system.  And with it comes a few new options plus a brand new mode – Group Mode.

ETTL mode.  This will trigger all the flashes to get an automatic exposure.  You can dial in exposure compensation if needed.  Ultimate dummy mode.  There is a note in the manual that states, “radio transmission wireless shooting using E-TTL autoflash is not possible” when using cameras released before 2012.  I’m not sure what this means, as I tested this mode on the 5d Mark II and it seemed to work.  I rarely use all ETTL mode, so I admit I’m not an expert.

Manual mode.  Can set up to three different groups of flashes at manual power settings.  You can control the flash power level remotely for your flashes with a quick button press or two and a flick of the dial.  Awesomeness.  Compatible with the 5d Mark II.

MULTI mode.  I never used this much, but I’m going to try it more this wedding season.  It’ll send multiple flashes during the exposure, like a strobe.

GROUP mode.   This mode is the bread and butter of this flash.  Group mode allows you to control up to 5 separate groups and set each group to either ETTL, Manual, Ext.A, OFF.  You can dial in the exposure compensation or manual power settings and it’ll change the power levels of your slave flashes remotely.  There are some definite creative possibilities available with this mode if you use your imagination.  Sadly this mode is not available for any Canon cameras models older than 2012.  So it just works on the 5d Mark III and 1dx for now.

The Good

New Menu System.  It’s not perfect, but it’s much better than previous flashes.  It’s much more intuitive to use.  They also made it fairly easy to toggle if your master flash will fire or not.  You literally just have to tap two buttons.  This is a feature I use EXTENSIVELY.  You can see where it is on the “MENU 2″ in the above picture.  With the 5d Mark II, I either had to dig through the on-camera flash menu or turn off the flash (which unfortunately disabled focus assist).  I love how readily available the option is.  If they could add it to the first set of menus, I would be swooning.

Sync on the 5d Mark III (and presumably the 1dx).  All other radio triggers have maxed out a full sync on 5d series cameras around 1/160.  A full power flash on the 600EX with radio can fully sync on the 5d Mark III at 1/200 sec.  That gives us 1/3 more stop to overpower the sun or slow down any ambient-lit subject movement.  CyberSyncs and RadioPopper JrX sync at 1/160 on my 5d Mark III.

High Speed Sync up to 1/8000.  I never use HSS, but it’s there and I tested it up to 1/8000 on the 5d Mark III.  HSS doesn’t appear to work when radio is used on the 5d Mark II or camera models released before 2012.

Ability to have 2 or more master flashes with different settings being used concurrently.   This is pretty awesome for those who work with another Canon shooter.  Each shooter can control the settings and power levels of the slave flashes.  It’ll automatically and instantly flip back and forth based on who triggers the flash.  Canon really got the remote power control system down.

Retains your settings when you turn off the flash or change batteries.

Memory setting.  You can program your 600EX to remember a certain set of settings.  So say you have a typical reception scheme.  You can set group A to ETTL, group B to 1/32 manual power, group C to 1/16 manual power, etc.  You can store these settings in memory, so that you’ll be ready to roll when the schedule’s running tight.  Just raise the light stands and go.  I don’t know how many studio photographers would use the 600EX-RT, but I could see this being useful to save studio lighting settings.

LCD colors.  The LCD changes colors depending if the flash is running as a master or slave.  Brilliant.

Optical wireless mode works with the legacy Canon flash wireless system.  I highly doubt I’ll use this feature, but some people probably will.

Sync Light.  There’s a green (or red) light on the back of the flash indicating if you have a radio sync with other 600EX-RT flashes in the area.  This is great to tell if you’re out of radio range or if your other flashes are turned on.

One set of batteries.  No extra or separate batteries for radio triggers!  It’s all self-contained.  You’ll only need AAs.

Can trigger the shutter of a remote camera using the radio system as long as you have the applicable cord.

Uses the same battery packs and has the same connections as the 580EXII.  I have battery pack, so this is a good thing.  The flash also retains a standard PC-sync port.

Neither Good, Nor Bad

Range.  I think range could have been slightly better.  It’s not bad, but it’s not nearly as good as CyberSyncs (only other system I tested for this review).  I did two tests for range.  My first test turned out much better than my second test.  I’m not sure why this was.  It was the same location, different days.  On the second test I raised the flash to around 10 feet, whereas it was closer to 5’ on the first test.  Not sure if that made the difference.  I’m supplying the far less optimistic numbers from my second test.

  • 30 meters – Flawless operation
  • 40 meters – Occasionally lost sync and the test button occasionally stopped working, but slave flash was reliable when triggered for a photo
  • 50 meters  – Sync and test button were intermittent, occasionally took an extra frame or few seconds to remotely adjust flash power, but the system had good reliability when triggering the slave for a photo.
  • 60 meters  – Reliability dropped off fairly dramatically.  Everything worked about 50% of the time.

I’d like to test the range in different environments.  It’ll also be interesting to see how it works at venues where there may be significant radio interference.  My personal conclusion was that even in very large ballrooms, I should be fine.  It seems the 600EX is sending a lot of information back and forth to keep synced and adjust power levels.  Even when the sync light is intermittent, the camera can often trigger the slave flash for a photo.  The 600EX just doesn’t have the range of some simpler triggers.  For reference, CyberSyncs were 100% reliable to exactly 100 meters.  Then reliability dropped off very, very drastically.  I didn’t try the CyberCommander.  I know the CyberCommander has a limited distance due to the increased bandwidth needed.  The 600EX-RT probably has a similar problem.

No real upgrades to the actual flash from the 580EXII.  The 600EX really feels like a 580EXII when you use it.  Recycle time and flash power are identical.  The only differences are the zoom range was extended and the zoom operates quieter.  I guess if it aint broke…?

Setting power levels remotely.  While the ability to set slave power levels remotely is a huge plus and it’s fairly easy, this feature isn’t quite as easy as with the CyberCommander or JrX knobs.

The Bad

Sync on older cameras (such as 5d Mark II) is a problem.  Oh, this is almost a deal killer.  It’s bad.  With my testing, to FULLY sync a full power slave flash with a 5d Mark II using the radio features of the 600EX, you have to set your shutter to 1/100(!) or slower.   I noticed no difference between 1/80 and 1/100.  1/125 isn’t bad, but by 1/160 a shadow on the bottom of the frame is quite noticeable.  So 1/125 is probably usable and 1/160 in some situations, but know the shutter shadow will be there.  You’re going to have to keep at 1/100 if you’re shooting on a seamless or in any critical applications.  You may want to keep a set of third party radio triggers if you still shoot with an older camera and need more sync speed.  Keep in mind, these test photos aren’t perfect.  They were just for personal use before I knew I was writing the review.  But the differences are MUCH more noticeable at a larger size and especially when you flip back and forth.  I haven’t tested any other cameras, except for two 5d Mark IIs.

Some modes and features, such as group mode, are unavailable on all cameras except the 5d Mark III and 1dx.

No triggers to use with off-brand or legacy flashes.  Canon hasn’t made (and probably won’t make) any radio receivers to trigger studio strobes or other flashes.  This also means you can’t use a light meter with the 600EX-RT.  You CAN hook up a Pocketwizard Plus, RadioPopper JrX, or CyberSync trigger to the sync port of your camera and then trigger slaves with a concurrent system if you want.  Not ideal.

No trigger for Nikon shooters.  I haven’t tested the ST-E3-RT or 600EX with Nikon cameras.  I’m guessing that even if they do work, all the features won’t be there.  I’m fairly confident we won’t get an easy way to share our lights with Nikon second shooters at any point.

Slightly harder to manually change power levels on the back of a slave flash in manual mode.  This can make a difference if you use an Apollo softbox or have the light very high on a stand.   But in those situations, why not use remote control from the master flash?  To adjust manual power on the 580EXII, you simply have to find the dial, hit the button, turn the dial as many clicks as you want and you’re done.  With the 600EX you have to hit one of the menu options before turning the dial.  Since there are more buttons up there, it’s SLIGHTLY harder to find.  Overall, this issue is small potatoes, but worth noting for those that like to manually set the flash power levels on their slaves on the actual flash and not set levels remotely.

ETTL.  I don’t know why, but Canon ETTL has historically always gotten it wrong when you bounce.  You still have to dial in +2/3 to +1 stop exposure compensation on average.  It’s fine since I’m used to it.

ST-E3-RT doesn’t have focus assist.  The ST-E3-RT is basically a 600EX-RT without the flash head and focus assist.  Why didn’t canon keep focus assist on this?  The 5d Mark III has good autofocus, but I still use focus assist when the sun starts setting.  Most of my shooting outside is around dusk or after dark, so I’ll be skipping the ST-E3-RT.  Bummer.

The menu system is much better than the 580EX, but that isn’t saying much.  The menu system could be improved.  It seems designed by engineers rather than photographers.  The menu is usable and it works fairly well, but gosh, haven’t they ever used an apple product in Japan?

Second curtain sync doesn’t work in radio mode.

The gel holder is a joke.   Canon only includes two gels.  One gel is similar to full CTO (just eye-balling) and one is about 1/8 or 1/16 CTO from what I can tell.  There’s barely any density on the lighter gel and it’s worthless since hot shoe flashes don’t have perfect color balance across the power spectrum to begin with.  They should have include a full CTO gel, a 1/2 CTO gel, plus at least a fluorescent green gel.  2012 and newer model cameras are supposed to sense a gel there and adjust the auto white balance closer to tungsten.  I haven’t tested it extensively.  It might work, but it’s much more of a pain than the custom Velcro gels I’ve been using for years.  I shoot RAW, so AWB isn’t a huge issue.  I should note that if you put your own gel on, you ideally have to disable the gel compensation feature entirely if you want the AWB to work properly.  Too much effort…  One other problem I noticed is the gel doesn’t like to lay flat over the flash head in the holder.  So you likely will get light leaks of ungelled flash color off to the sides.  My velcro gels are much easier to use.  See below.

Cost.  There are many other radio and flash options out there and some have similar features for less cost.  I believe the 600EX-RT will make it up in reliability, but it’s still an issue.


For the right photographers, the 600EX-RT will be a wonderful tool.  You get remote flash power control, flexibility, total creative control, all in a convenient and compact package.  No more fiddling with wires, connections, and radio triggers.  This system is built for speed, portability, and reliability on the go.

For those who don’t own a 5d Mark III, 1dx, or newer Canon camera, this flash system is wayyy less cool.   I haven’t done extensive testing on different camera models, but the sync speed is probably going to be a problem for many older cameras.  You also won’t have access to all the snazzy modes and features.  Price will be a major concern for many.  Let’s face it – even a fantastic product like the Einstein is cheaper than the 600EX-RT.  And for about $140 you can buy both a powerful manual hot shoe flash and a (fairly) reliable radio trigger.  But if you have to work fast, you’ll appreciate the 600EX-RTs.

I personally have some creative ideas on how to use the new 600EX-RT in my wedding photography this year and I hope we, photographers, can use new tools like this to further our craft.