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Review: Pixel King Flash E-TTL Triggers

by Philippe Dame on May 25th, 2012

I recently posted an extensive blog entry citing six ways to go wireless with your flash and in that post I mentioned my recent purchase of the Pixel King Flash E-TTL Triggers. In this post, I’ll tell you what they do and give you my take on them.

Overall, Pixel King flash triggers work as advertised. They’re more convenient than manual-only radio triggers and they’re a relative bargain compared to radio-based TTL alternatives.

Who is Pixel Enterprise?

First of all, who exactly is Pixel King Enterprise Limited of Hong Kong? From what I gather, they’re effectively a low-cost manufacturer of camera accessories focused primarily on radio-based triggers for flashes and cameras. They also make inexpensive battery grips.

They’re most famous for reverse engineering the TTL protocol for Canon and more recently Nikon and Sony to create a line-up of compelling radio-triggers at reasonable prices.

Although you can buy Pixel products certified for North American use, you won’t find many mainstream retailers carrying them. That said, I was surprised to see that my local camera store, Henry’s, does stock them (unfortunately they sell them at nearly double the online price).

I bought my trio (one transmitter and two receivers) for only C$238 at – it’s a tiny online reseller out of Montreal. Please see my conclusion for more shopping links.


To provide a quick overview of the Pixel King setup, I created a short video to show you what they look like and how the units attach to your camera and flash. In the video, I summarize how they function and point out a few of their capabilities and limitations.

In short, a Pixel King package is made up of a transmitter and a receiver. The transmitter sits in the camera’s hot shoe while the receiver attaches to your flash. Cables are provided to attach the receiver to a strobe and other compatible light accessory (see the section on accessories below for more details).

There is indeed a Pixel King model for Canon, Nikon and Sony as each vendor’s flash TTL system is unique. Their Canon model came out first so it’s a bit easier to find and read about.

You must buy a receiver for every flash you wish to control off-camera. There are many vendors selling packages with a transmitter and multiple receivers. If you’re paranoid about equipment failures, you may want an extra transmitter and extra receiver but then your costs start to creep up.

Size, Weight & Build Quality

One thing I noticed right away is that the Pixel King units are quite large. You can see my comparison shot below alongside a Canon Elph point-and-shoot camera. They are, however, extremely lightweight even with two AA batteries. They’re so light that they almost feel cheap but the build quality is quite reasonable overall.

Physical Operation

Operating the Pixel King is pretty straight forward. There’s a on/off power switch on the right side, a button to verify/change groups and another button to verify/change radio channel.

When you attach your flash to the receive, there’s nothing to set on the flash. It  thinks it’s in your camera’s hot shoe. There’s no need to place the units in slave mode, set groups or pick channels. All of this is handled by the Pixel King receiver.

On the bottom of each unit is a standard flash mounting foot with a lock pin. It has screw-based locking mechanism so it can be firmly attached. If anything, it can get too tight and you may need a coin to loosen it at times. The foot includes a 1/4″ screw socket for direct attachment to any standard tripod or light stand without a cold shoe adapter.

Flash Groups

The right side of each receiver has LEDs that indicate the receiver’s group assignment (A, B or C). The assigned group can be quickly changed with a press of the dedicated “GP Set” button. Again, you do not place your flash into “Slave” mode – you simply turn it on and keep it in its default mode.

A group setting can also be found on the transmitter so you can quickly configure a subset of the groups to be triggered (i.e. in case you wish to omit one quickly). The transmitter supports all possible combinations: A, B, C, A+B, B+C, A+C, and A+B+C.

Radio Channels

The “L1″, “L2″ and “L3″ lights on the left side of the units let you configure one of seven available radio channels. These exist to avoid conflicting signals from nearby Pixel King users or other interfering devices on the 2.4GHz band. As long as the left-side LEDs match on all units, they’ll communicate with one another. Changing the channel is done by pressing the dedicated “CH Set” button repeatedly.

Radio Range

Though untested by me, the stated range of the units is 100 metres (that’s over 325 feet). They run on the 2.4GHz band like your cordless phone and are digital in their communications. Given that range, they should rarely misfire under normal usage and will easily send their signals through the wall of your home or studio.

LED Status Indicator

A multi-coloured LED status light on the back of the units indicates when they are on standby (red) or actively communicating with one another (flashing blue). Thanks to a recent firmware update, it also reports a low battery state (I think that must be flashing red but I haven’t seen it yet).


One great convenience is that the Pixel Kings use standard AA batteries (2 each). This keeps it simple for packing extra batteries given your flash uses AA batteries as well. According to the manual, the transmitter and receiver will function for 300 and 200 hours respectively while in standby (based on 1.2V 2400mAH rechargeable batteries).

Focus Assist Beam

On the front of the transmitter you’ll find a focus assist beam which is a simple white LED light. It lights up when you press on the shutter halfway to help you acquire focus in low light. It’s probably not as ideal and effective as the infrared light on most flashes but it’s better than nothing.

It’s worth noting that when you do press the shutter halfway, the receiver tells your flashes to illuminate their IR assist beams. If your flashes are pointed the right way, that may help you focus as well.

PC Socket Connector

Both the transmitter and receiver are equipped with an industry standard PC socket (see photo below). On the transmitter it’s used for receiving a trigger signal while on the receiver it’s used to send the signal to an attached strobe (i.e. in lieu of using the hot shoe). See the accessories section below for more details about using that socket and the adapter cables that are included.

Mini-USB Port

Both units also have a standard mini-USB port which permits firmware updates. I recently did such an update successfully but it did require I use Windows and I’m on a Mac. It seems Pixel King is release updates regularly and that’s a good sign.

Transmitter Hot Shoe

There is a hotshot on the transmitter and you might think you can put your flash in there – but you can’t. I think it’s for some future accessory by Pixel. The manual states it’s “only for use with N-ETTL (flash power controller)”. I’m not sure what that is (if you know, let me know). In effect, you won’t be able to combine on-camera and off-camera flash. If you have two flashes, buy an extra receiver.

Bundled Accessories

Shown above, you can see the mini-stand included with each receiver. The foot that came with your flash will probably suffice but this one is probably a bit more stable.

The transmitter and receivers each come with a hand strap the box includes a vinyl zippered pouch (not shown). The hand straps are not that useful given you don’t carry these units in your hand like a point-and-shoot camera. I left mine on but they do get in the way so I’ll probably take them off soon.

Each receiver also comes with the two adapter cables to allow triggering of devices that don’t fit in the hot shoe. There’s no TTL communication at this point but you can trigger nearly any strobe or other flash unit with one of the two connectors provided.

Above: “PC to 3.5″: PC Screwlock to 3.5mm mini phone jack

Above: “PC to 1/4″: PC Screwlock to 6.35mm phone jack.

Features and Compatibility

When attached to a compatible flash unit, the Pixel King offers the following key features:

  • Radio-based triggering of your flashes within a 100m range (over 325 ft)
  • Wireless E-TTL flash metering (limited to one power setting for all flashes, ratios are not permitted)
  • Flash exposure compensation in E-TTL mode
  • Flash exposure lock in E-TTL mode
  • Manual flash power settings (unique power level for up to 3 flash groups)
  • All shutter sync options: 1st curtain, 2nd curtain and high speed sync
  • High speed sync up to 1/8000 second
  • Flash zoom control (“auto” and manual zoom)

According to the manual, the Pixel King receiver is compatible with the following third-party flashguns and their TTL capabilities:

  • Metz
  • Sigma
  • Sunpak
  • Nissin
For Canon owners with “EX II” series flashes, you get the major added advantage of on-camera control via the existing “Flash Control” menu. From what I understand, there’s no such menu in Nikon so this is not a feature of the Pixel Kings for Nikon. I’m not sure what the limitations are with Sony – if you know, please post a comment.

Feature Limitations

Pixel King’s manual clearly states it has some limitations and those are as follows:
  • No support for ratios in E-TTL mode (e.g. you can’t specify 2:1 for A:B)
  • Cannot mix E-TTL and manual modes at the same time
  • Incompatibility with camera’s built-in optical flash-triggering system (obviously)
  • No support for flash exposure bracketing
  • No on-camera control of flash settings without “EX II” flash units
  • No support for stroboscopic flash
  • Transmitter’s built-in hot shoe cannot accept a flash

Manual vs. TTL Control

Many people I know, and photographers I follow online, consider themselves “strobists”. This means they’re masters of small flash units for advanced off-camera lighting. Most of these people do all their work with manual power settings on their flashes and use radio triggers solely to fire the flashes. They often rely on light meters to asses the correct exposure.

Such strobists will easily overlook the benefits of Pixel King triggers as they don’t need or want “TTL” flash metering. They will buy something less expensive like Cactus or Yongnuo branded radio triggers. Some will spend more and get the popular PocketWizard Plus II or Plus III transceivers.

What these people might be overlooking is that TTL-enabled triggers mean the triggers speak the camera’s proprietary two-way flash language. It’s the reverse engineering of this protocol that allows the units to deeply integrate with the camera. Canon owners of “EX II” series flashes get the added advantage of full flash control from the camera menu (that’s not trivial).

In manual mode, you can configure the power setting of each flash group without ever touching the flashguns. You can also set 1st curtain, 2nd curtain or high speed sync remotely and then also change the flash zoom level… all remotely.

This extra communication might also help the Pixel Kings achieve a maximum sync speed of 1/8000th of a second. A PocketWizard Plus III, for example, tops out at 1/250th sec. and the Cactus v5 triggers have a max of 1/1000th sec.

For me, the ability to set the manual power levels on the camera for each group is a major benefit. I will never have cross the room or reach up to my boom to access the back of the flash unit and change its power. I can rapidly experiment from the camera and adjust to changing conditions without making people wait.

I do of course appreciate the TTL capabilities and 1/8000th sec. high-speed sync. I think I’ll use those primarily while I’m outdoors (i.e. less of a fixed studio setting). Whenever the subject-to-flash distance is constantly changing, TTL avoid many hassles. When outdoors, your flash is often used as a fill light and must be used with high shutter speeds. I want my flash trigger to keep up with me, not limit me.

To get a feel for what “on-camera” control really feels like, watch this short video I prepared below. I walk through some the options you get with the Pixel King on a Canon 7D and two “EX II” flashes (one 580EX II and one 430EX II). You will notice a bit of flakiness with the camera menus but it’s not unworkable. Hopefully Pixel is aware of the issue and will patch those quirks via a firmware update.

Overall Weaknesses

The biggest weakness of the Pixel Kings is its lack of ratio support in E-TTL mode. It would be amazing if you could set an A:B ration like 2:1 (i.e. one-stop more light from flash “A” relative to flash “B” while the entire power levels are still set automatically). It’s not a must-have for me but it’s the biggest nice-to-have that’s missing. Perhaps a firmware update will fix that but I figure it’s a major limitation of their design.

Other than that, pro photographes would probably prefer that the units be “transceivers”. That means one unit can be both a transmitter and receiver as needed. This makes it easier to prepare for equipment failures as you’d only need to buy one extra unit for backup purposes. As it stands now, you’d have to buy an extra transmitter and receiver to cover your bases.

One minor issue for me is the size of the units. They’re light but they’re not terribly compact. I like that they take standard AA batteries but I’m sure they could be shrunk down with a bit more engineering. I’d be fine if they took AAA batteries instead of AA (as long as they don’t use flat batteries).

And finally, Pixel King screams “Made in China” when you read the manual (was it machine translated?). I took a snapshot of one page for the fold-out manual so you can see what I mean.

TTL-Capable Alternatives

Pixel King has a predecessor called the “Pixel Knight”. It’s smaller than the King but I think it’s less capable overall. It also uses flat batteries which I would definitely avoid.

In addition to the Knight, there are non-Pixel options if you’d like to compare TTL-capable flash triggers on the market today. You’ll find, however, that most other brands are much more expensive (they were out of my budget for sure).

One big advantage of the three non-Pixel alternatives listed below is that they can all do ratios in TTL mode. If you really need that capability, you might go with one of those but be ready to pay for it.


Overall, I love having radio-triggers. I grew weary of Canon’s built-in optical system and its misfires pretty easily. Outdoors, the optical system becomes unusable and you can forget about placing yourself below or in front of your flashes. Radio-based triggers simply don’t fail as line-of-sight is not needed.

A move to radio-based triggers usually means given up on TTL and on-camera control. Luckily, Pixel King present an affordable option that is both radio-based and TTL capable. The Canon units, when used with EX II series flashes, gives you back that on-camera control.

Though it’s not perfect and it lacks TTL ratios, I would still strongly recommend Pixel Kings to anyone considering a more basic radio trigger. For $150 or less, you can get a transmitter and receiver. For $240 or less, you can get a transmitter and two receivers. These are good prices relative to alternatives like PocketWizard FlexTT5 transceivers which will run you $230 each (i.e. $690 to control two flashes).

If I’ve sold you on these and you live in Canada, avoid Henry’s and checkout If you’re in the USA have a look at Amazon and eBay for the best deals. If you live elsewhere, just Google “Pixel King” and your country name and I’m sure you’ll find some nearby.

If you have radio-based triggers, let me know what you have and how you like them by commenting on this post. If you have TTL-capable radio trigger, I’d really like to hear about your experience.

  • Pat

    Nice review Phil!!

    In your demo on in-camera menus, that error you got “incompatible flash” … THAT’s the error I would get with my flash down in Cuba!!! 

    Many readings on the internet about it brought me to disassemble my 580 EX II flash foot and perform the following on it:

    So far, so good… just in case you get strange glitches sometimes… it might have something to do with that…. Dunno.

  • Pingback: Six Ways to Go Wireless With Your Flash | Learning DSLR()

  • Vince Tieu

    hi Phil,
    I appreciated the very thorough review on your post about “6 ways of going wireless with your flash”. This follow-up is awesome. Question comes to my mind is whether this indeed fits into the Qbox bracket?

    • Philippe Dame

      Sorry, notifications on my comments got shut off somehow. Catching up now! Yes, it should fit fine in the QBox. The whole thing just gets taller but you can adjust the bracket to center the flash into the opening on the back of the softbox.

  • PGT94

    Thanks for the review.

    I know it is an old thread but thought that I’d share a bit of my experience for anyone who might bump into this like I did.

    I bought a set of Pixel King transmitter and receiver and another receiver.

    One of the receivers wouldn’t sync, so the images taken would have a black line on one end, so I ended up having to return it and get another one. The replacement one has been working fine.

    Very happy to be able to sync faster than 1/1000th, as my camera is only as fast as 1/200th.

    So, do the test ASAP and carefully when you buy this unit.

    • Philippe Dame

      Thanks. That’s good to know. I think mine are OK in this respect but good idea to test out the units right away at high shutter speeds. Do you experience the menu issue I show in my menu video above?

      • roya

        I try to experience the menu you show above, and i don’t anderstand what i do wrong? i have 7D also, three flashes 1 580EX II and 2 yongnuo 560III
        i put the king pro transceiver on the camera hotshoe. i can see on the 7D the menu open(external flash func setting) but i can’t switch form ETTL to Manual or any changes that i want to set. do you know what this error mean?

        • Philippe Dame

          Sorry, I have no clue.

  • HH

    They are compatible with NEX7. Recently the firmware update is available but its.exe always FAILs when doing the update.

  • akam

    i have a canon Speedlite Transmitter ST-E3-RT and one 600ex-rt flash, I want to buy extra strobe light, can I buy Pixel King Wireless TTL Triggers receiver to use canon ST-E3-RT transmitter as a master and Pixel King Wireless TTL Triggers receiver for another strobe light as slave and use 600ex-rt flash as a slave?

  • WH

    Great article. Thorough. Thank you for writing it. Looks like the new Pixel King Pro fixed one of the issues you found to be a weakness – making the devices transceivers – and another you mentioned earlier in the article – firmware updates via the Mac OS. That’s good to see. I’m curious though if they fixed the ratio issue. Can’t quite tell on their web site. They don’t mention it directly on their web site, but there is an “Output Ration Function Setting” when looking at the diagram of the device. You’re comment about it “screams” of being made in China is right on. The web site appears to be interpreted as well. It’s a funny read. As an extension of this “loss in translation” I wouldn’t be surprised if such an important feature was omitted. I would be interested to hear your thoughts on the Pixel King Pro improvements and if they fixed this major issue as well. If they did, the it seems like it would be an ideal solution. Thank you.

    • Philippe Dame

      I’ll have to read more about them. Thanks!

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