Canon Has Officially Dropped 'Master' and 'Slave' Terms

Canon Has Officially Dropped 'Master' and 'Slave' Terms

Since the global response for Black Lives Matter, many industries, including photography, have been shifting for the better. So, it's welcome news that Canon has officially dropped their master/slave terminology.

The terms "master" and "slave" used to be and in some cases still are commonplace in photography, especially when it comes to flash units. A master flash gun usually controls the trigger of another flash gun called the slave. This technique is used to synchronize multiple off-camera flash devices and is commonly used instead of wireless (or wired) triggers to either save time or money.

Flash guns set to master can be used to trigger other flash guns set to slave mode where wireless triggers, like this Godox XProN TTL, aren't used.

I spoke recently about my reservations with the master/slave terminology and some other issues I had with specific terms within the photographic community. I've since been in touch with Canon who confirmed, much to my surprise, that they've actually dropped the master and slave terms. In fact, they dropped them around the end of 2017. Here's what a Canon Europe Spokesperson had to say:

Canon started to phase these [terms] out since the end of 2017. [In] all new products and materials, these terms are no longer used. Products released before this time, and still available, will still have the term as it’s often a physical part of the LCD display so can’t be changed by firmware etc.

So, why then wasn't I aware of the terms being changed? I'm sure this is news to most of you as well. Well, they went on to say that the terminology change isn't yet immediately obvious to most customers because the terms are mostly used with flash guns, which are presumably less popular than the cameras and lenses. To compound this issue, the most popular flashes were launched pre-2018, so when customers use the manuals, the terms are still there.

The popular Canon Speedlite 600EX II-RT speedlite was released in 2016, before Canon officially dropped the terms "master" and "slave."

Many photographers buy used gear, so will also not notice the terms change either on devices or in manuals for a little while, until the newer models start to drop in price and are more widespread in the secondhand community. But until then, at least it's good to know that Canon has dropped the terms. Who knows, maybe old manuals and flashguns will become more museum pieces, holding historic knowledge for the photographic community at large?

Jason Parnell-Brookes's picture

Jason is an internationally award-winning photographer with more than 10 years of experience. A qualified teacher and Master’s graduate, he has been widely published in both print and online. He won Gold in the Nikon Photo Contest 2018/19 and was named Digital Photographer of the Year in 2014.

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Oh boy. Cue the outrage.

I always found 'commander' and 'receiver' to be better terms anyway.

I think "transponder" and "receiver" makes more sense.

Those are good too.

I'm sure you meant to write, "better" but it's all good! jk ;-)


‘Transmitter’ or ‘transceiver’ would be more accurate terms. A transponder is a dummy device, which sends out a translation of an incoming signal. Indeed, ‘controller’, is a great term, as it does more than simply transmits what it is told to do, but is in charge of all the receivers, sending the appropriate signals to the appropriate strobes, and reporting the settings of each strobe.

So true. Plenty of more informative, less antiquated (and insensitive) terminology that can be used.

Yeah, I mean master/slave isn't even as straightforward or as simple to understand, which does matter for various reasons, including photographers new to using flash.

Not that I'm defending the terms but, that doesn't make any sense. How is the term "camera" straightforward or simple to understand, if not by the fact everyone already knows it? "Master" and "Slave" are fine for the purpose, notwithstanding their unfortunate connotations.

He didn't say they were not understandable at all. He said they were more informative. And they are. Transponder/receiver can't be misunderstood unless you don't know what words mean.

I would argue, "transponder", but not "receiver", isn't a widely used/understood term. It is an interesting point but I hope the government would be disinclined to fund such a study. ;-)

It's hard for me to imagine someone knowing the meaning of "transponder" and not knowing the meaning of "receiver" used in the same context.

Clearly, I was confused about "transponder" ;-) I meant "transmitter" but misstyped.

Only for the fact that a "camera" is pretty narrowly defined - if I were to define it, a tool that senses light to produce an image or images, usually in the visible spectrum! "Master" vs "slave" is a relationship between two things - usually people! - and it's closest analogue is among the shittiest ways people have exploited one another.

I was referring to the word, camera, if one had never heard of such a device (silly, I know). Perhaps "Portable light recorder", although that doesn't exactly roll off the tongue.

If you're going to compare exploitive relationships, it's certainly shitty but I can think of worse. Of course, exploiting someone in a particular way doesn't negate the possibility of other, even worse, methods which I'm sure has occurred from time to time but have no idea of the frequency, not that it matters to those effected. What I mean is: in it's most benign form, slavery isn't significantly different from some employment situations you might encounter today but other, ancillary, elements are truly horrendous.

This master/slave nomenclature has been all over the digital world for decades and it has always bothered me. Newer interfaces use terms like 'controller / peripheral' or 'root / end-point', stuff that still makes sense without a human bondage metaphor.

The other thing that has always struck me as weird is the male/female genital metaphor for cables and connectors. That's the best we can do? I use pin and receptacle whenever I talk about it.

I find that a bit odd too. I give it a bit more leeway for the fact that the male/female reproductive method is found throughout the animal kingdom (and other kingdoms!) and is not inherently rooted in exploitation. That said, there are better terms out there that don't immediately reinforce the male/female relationship as being based primarily around insertion!

The only defense of male/female I have is that it is applicable to so many more things than just cables or electronics, beyond which pin/receptacle wouldn't make any sense. I think it's the only term that could apply to all of those different things, from a cable to a pipe fitting.

Plus, those terms are not offensive in the way master/slave is, and as Gary says, male/female is not exclusive to humans.

Mostly though, it's point #1 - I can't think of other terms that would be so universal.

This is beyond silly. The terms were very descriptive of the relationship between the two, and a heck of lot more obvious to the newbie than 'transponder'/'receiver'.

This is taking Political Correctness way beyond anything a rational person would consider appropriate.

You don't mind if your boss calls you slave then, right?...

Compared to "receiver"? Hmm...

To be fair, if your employer does a lot of shipping volume or is an NFL team, that might already be your job title.

As one comedian has recently said about cancel culture, "Everyone is an asshole if you study them closely enough."

Speedlites are not people, they don’t have rights or feelings that can be hurt. And how are we going to call master and slave cylinders in hydraulics. How are we going to call the people in Eastern Europe instead of the Slavish people.?
Slavery is a very bad thing, and it still exists, we should concentrate on that. Racism also a very serious subject and seems to be increasing and should be combated. Renaming strobe units doesn’t help imho.

Seriously tho, I've never actually called them master and slave, simply transmitter and receiver.

How is slave/master more obvious to a newbie than "transponder" (which is quite clear as to what it does) and "receiver" (again, extremely damn clear).

When I first learned flash I'd read about slaves or using a flash to trigger slaves and I was confused as hell.

When I first learned about flash, the terminology was the least of my confusion! ;-)

That's legit funny

ok this is very true hahaha

Most cameras/strobes never act as a “transponder.” I do not think that word means what you think it means.

Transmitter, or transceiver would be more accurate terms.

Won't it be nice when some new hysteria takes over the stage, and this ridiculous virtue-signalling about race is over?

It seems to me, a great number of white guys have done that very thing. Perhaps you meant "all" white guys or even "all people"?

Unless Canon Inc starts hiring a lot more Filipinos and Koreans, it's just virtue signaling.

That's exactly why I made that comment. I've spent considerable time in Japan, South Korea, and the Philippines...and I'm aware of what they broadly think of each other.

Are you saying that it'll be nice when white people can stop thinking about this uncomfortable stuff and go on about their lives? Some minority people don't get this luxury.

Or maybe move ahead to serious discussion of meaningful action on the complex issue of racial disparities - and, eventually, improve people's lives.

I hope that there are no statues of camera flashes out there, we would have to tear them down.....

While such moves are clearly aimed at getting ahead of backlash and have no real substantive value towards change, keep in mind from whence the country has come and how some quarters remain ignorant of that past. Context is king. I hadn't given this terminology a second thought until this article. Canon can call it anything it likes. But, if Canon's social behaviors (I have no idea what they are) are above reproach, a naming convention is irrelevant.

In the 3D world it's always been known as parent/child, which I always found kinda cite.

I never thought about it but, that makes less sense than master/slave because in lighting and 3D objects, assuming they're set up correctly, the subordinate object ALWAYS obeys its superior; my children only rarely, ever obeyed me! ;-)

Slaves sometimes revolt as well.

Good point.

This whole political correctness is getting galactically stupid. Has anyone watched the comedy "White Chicks"?? No? Doesn't that offend you? How come? If we are going to be social warriors let's be fair to everyone. I'm waiting for some PC warrior to ban the use of black color altogether because it'll be deemed racist. For f**ks sake...

You and a lot of people are coming to terms with a history in which you're not informed.

When I was in High School, I did ridiculously well in Geometry but fairly sucked in Algebra, the reason being, while I understood the formulae, I could never relate them to the real world, while in geometry, it jumped out at me. My Geometry teacher refused my request to take Algebra II, the following year, insisting I jump over it to Analytical Trigonometry. After he signed off on that, I changed it back to Algebra II. It didn't help.

I'm not sure "coming to terms" is the correct phrase here.

I looked it up too. ;-) I suppose it applies to a great deal of the population but not to others and Przemek, in particular. The key elements seem to be "accepting" and "difficult" or "uncomfortable". I don't claim to read minds and don't mean to put words into Mr. Lodej's mouth but his words don't seem to indicate acceptance or any effort to achieve it. Furthermore, I have no idea if the history, to which you refer, is difficult or uncomfortable for him. While my assumptions, based wholly on his comment, may in fact be wrong, that may also be the case with yours, which is why I wrote, "I'm not sure". :-)

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