Pixel TR-331 TTL Wireless Flash Trigger Part II

This Bites!
This Bites!

Pixel TR-331 Wireless Flash Trigger For Nikon TTL

The Tao of Wireless Flash Continued…

In conflict, be fair and generous.

I have now taken many, many photographs with the Pixel TR-331 Wireless Flash Trigger set. At least I would have if the transmitter and receiver were doing what they are supposed to do. Rather than bore you with two days worth of trial and error results, I’ll just say that I have come to the conclusion that my transmitter (TX) and or receiver (RX) are either defective or were damaged in transit. My best guess is that there is a short in the TX between the circuit board and the hot shoe. Of course this all chafes, bites and stings but it is not the world’s worst problem and can be easily resolved. It is very frustrating when something works, then sort of works, then stops working, starts working briefly and then finally stops working again. I’m going to set those issues aside for the moment and tell you what I have learned about these triggers. What follows is my personal opinion, probably flawed and about the best I can do.

I like these triggers. They seem to mimic the iPod TouchÔ design theme with flat, glossy black (plastic) tops. The digital display and function buttons make setting the modes and channels on the TX and RX units a breeze compared with the tiny switches found on many of the other Chinese wireless triggers. The Pixel TR-331 triggers add the ability to transmit the camera flash menu settings to the off camera flash. Any changes made in the flash mode menu on the camera are sent to the off-camera flash and appear on the flash menu display as though it were sitting on the camera hot shoe. You can control functions like red-eye-reduction, slow sync, rear sync and any available combinations of those options that are included in the camera menu. The TX and RX also recognize when the camera is set to FP HSS mode. You can sync the flash up to the camera’s maximum shutter speed, which is useful for taking flash photos in bright sunlight at low apertures.

A lot of people were hoping that the advertised TTL function meant that the TR-331 would also allow access to the Nikon CLS flash features or at least permit some sort of hybrid arrangement that might combine radio frequency signals to a Nikon commander flash at increased ranges and then enable the commander to send CLS information to several groups of slaves. The Pixel TR-331 has Master and Slave settings on the RX units but this only applies to TTL functions. Pixel has confirmed that there is no communication between RX units and that the Pixel master and slave RX functions are both controlled by the TX unit on the camera hot shoe. The current asking price of the TR-331 combined with the lack of CLS compatibility may be a deal-breaker for many photographers looking for low cost, acceptably reliable flash triggers. For the cost of one Pixel TR-331 transmitter and receiver set; you may be able to purchase four or more sets of the Yongnuo RF-602 triggers or similar units from Cactus. When it comes to low cost flash triggers, emergency spares and backups seem to be the name of the game especially when replacements can take several weeks to arrive in the mail.

It seems as though there is no free lunch when it comes to wireless flash solutions. You have to learn to decipher the advertised features and then decide if these types of products will fill your needs. For instance, I don’t think that wireless flash triggers offer much of an advantage for wedding photographers who use mostly on-camera flash or flash mounted on a bracket to shoot TTL and bounce flash along with the ability to move quickly around a venue.  I’m not sure that TTL is extremely useful in general for off-camera flash, where you need to set groups of flashes to different power ratios for customized lighting setups. The ability to remotely control power level adjustments seems much more useful to photographers working alone and don’t want to waste time walking back and forth between flash units to make minor power level adjustments.

I feel like going for a drive and taking some photographs today. I’m thinking of making a bumper sticker that says:



Pixel TR-331 Wireless TTL Flash Triggers


  • Replaces dedicated TTL cable with wireless radio transmitter and receiver
  • Supports Nikon flash menu functions (slow, rear sync, red-eye-reduction, ect.)
  • Auto zoom mode on flash head with compatible flashes
  • Controls off camera Master flash output from camera flash compensation menu
  • Digital channel & mode selection through two simple function buttons
  • TTL and Manual transmitter modes
  • Master and Slave modes on RX units
  • Supports Nikon FP HSS high-speed sync mode
  • Locking wheel on TX and RX hot shoe foot
  • Backlight on TX and RX display
  • Programmable ROM may allow extra functions in the future? See jack on TX unit
  • Low battery / power indicator on TX and RX display
  • Advertised long battery life in standby mode
  • Uses 2.4 GHz frequency for increased range


  • No communication between Master RX and Slave RX
  • Does not support Nikon CLS Commander mode or groups (may be modified by future firmware updates)
  • RX display is difficult to see with the flash connected to the hot shoe
  • Nikon flash units obstruct function buttons when connected to RX
  • Possible quality control issues
  • Uses relatively expensive CR2 batteries
  • In-use TX battery life likely to be substantially reduced from stated standby times
  • No test button on TX unit, requires multiple shutter releases to test lighting levels
  • Feature set versus cost
  • Price per unit versus the competition


The Pixel TR-331 is a bit of a tease. It promises some very cool things and appears to be able to accomplish them. That leads people to believe that it can do other things that it can’t currently deliver and does not claim to. I don’t think any deception is intended. We simply seem to be the victims of our own high expectations, endlessly searching for the best of everything at the lowest possible cost.

I think the addition of factory programmable memory is a big step forward from previous simple wireless triggers used as replacements for pc sync cables. It shows what can be done even if all of our needs and wants are not included in the current feature set

After getting two defective (or damaged) transmitters in a row from two different companies, I am fairly frustrated by the whole world of wireless flash triggers.

For many photographers who want to experiment with off-camera lighting the Nikon Creative Lighting System is still the best and most reliable choice but only if you can afford the cost of Nikon flashes. If you currently have a Nikon camera with an on-board flash that can serve as a remote flash commander, you can buy one very nice Nikon SB600 for just slightly more than the current price of a set of the Pixel TR-331 wireless remotes.

Nothing is foolproof but if I had to make a recommendation at this point, I would be leaning towards Nikon CLS, especially if you are working at relatively short distances or indoors. Nikon CLS works as intended and Nikon flashes are here now. There is no waiting period required while the manufacturer works out the kinks in the product or delivery.

I’m sure I’ll have more to say in the future when I get my replacement triggers.

15 Replies to “Pixel TR-331 TTL Wireless Flash Trigger Part II”

  1. Too bad it has reliability issues, but looks like all chinese made triggers suffer from the same issues to some degree. You mentioned that “Any changes made in the flash mode menu on the camera are sent to the off-camera flash and appear on the flash menu display as though it were sitting on the camera hot shoe. You can control functions like red-eye-reduction, slow sync, rear sync and any available combinations of those options that are included in the camera menu.” – does the system support AF assist illumination when you press the shutter release half way?

  2. I’m trying not to jump to any conclusions based on one sample but it’s not encouraging. I would have expected that since I specifically told Pixel I would be testing these to write a review that they might have actually thrown some batteries in these and tried them in advance. Of course they may have found nothing wrong at that time. It is possible that extreme temperature change or vibration did them in on the trip from China.

    Intermittent electrical issues are tough to spot and diagnose. It took me two days before I decided it was a no go situation. Every now and then they would start working. Actually most of the functions work except the flash would not fire in sync with the shutter. I think that is caused by a poor connection to the hot shoe.

  3. Yes, perhaps you did have a lemon unit. So, is the AF assist supported or not with this trigger?

  4. Yes, I believe it is. The autofocus lights on the flash are activated by a half-press on the shutter button. Also the auto zoom function on the Nikon flash works when you zoom the lens on the camera. My only real issue is that I can not get the flash to sync with the shutter on the camera. I think that is due to a bad connection on the TX hot shoe mount but it could also be on the hot shoe of the RX.

    These are pretty cool triggers. I just happened to find the bad apple. I think the real issue may be cost versus value when compared to other triggers in this general price range.

  5. Thanks for the review and replies. I think I will wait until others have theirs on the market (I think Yongnuo will follow soon, but can’t confirmed). Right now I don’t like how Pixel selling theirs on Ebay: they are forcing buyers to bid for higher price, and there is no Buy It Now option so you have to no choice but to bid for higher price and wait till the auction is over (7 days). Personally I think the selling price is already too high, so it’s ridiculous to ask for even higher (by auctioning). Others will follow, and perhaps with better reliability and pricing.

  6. I’ve been trying to keep up with the discussion over at the strobist group on http://www.flickr.com and it has been recently reported that Pixel has made a firmware change that allows the triggers to work correctly with the Nikon SB600 flash units and possibly to enable some CLS functions to the master flash only. That may allow a hybrid arrangement of wireless and CLS working together to increase range and outdoor performance.

    I have not verified that the changes work. I’m waiting on Pixel to send me replacement units so I can run my own tests.

  7. So… any info on updates?

    Thanks for review, I’m looking for triggers – reading reviews, browsing forums… your’s is nice 🙂

    …as far as I understand, there is no way to control off-camera flash power output without walking to it and setting it manually, right?

  8. The Pixel triggers turned into more trouble than they were worth and I have stopped actively following their development. Lately I have been hearing promising reports about the new Photix triggers but I have not tested them.

    I like the Yongnuo RF602 triggers for working in manual mode.

  9. Excellent two-part review. It really helped me understand the TR-331 better.

    Much to my disappointment the wireless TR-331 underperforms both Nikon CLS and using a simple TTL sync cable. For me, it offers nothing significantly better than the $30 Yongnu RF-602Nwireless trigger. Both dramatically overexpose (flash at full power, showing no accurate recognition of in-camera metering) unless BOTH camera and flash EV are reduced by a factor of -3 (max reduction). In my experience, and perhaps contrary to yours, when I reduced the in-camera flash EV to -3 but didn’t make the same, corresponding adjustment to my TR-331 receiver-mounted flash unit (off-camera), I get an image that’s ridiculously overexposed.

    So, my question is, why did I spend $100 more for the TR-331 when I can’t make in-camera only exposure adjustments? More importantly, why doesn’t it meter sync as well as a TTL cable? After all, that’s what the advertised TTL capability of the TR-331 is supposed to be all about: TTL syncing that produces accurate flash exposures automatically. In my experience the only advantage, and it’s a tiny one for me, of the TR-331 over the Yongnu RF-602N is that it does allow for red-eye, slow and rear sync adjustments in-camera. That’s hardly worth the $100 extra to me.

    Is there something I’m doing wrong or is the TR-331 simply way overpriced?

  10. You made several good points. First, remember that exposure compensation on the camera is universal in that it affects both the camera and the flash, while exposure compensation on the flash is additive. You are really dealing with two separate exposure systems and in your example the exposure compensation is doubled. 

    It Also seemed to me that the original 331 set i tested was causing my flash to dump a full power burst instead of actually using TTL to measure the exposure. You shouldn’t have to second guess the system on an evenly lighted scene. 

    I recently recieved an updated set of 331 triggers and I will be testing the current version for the exposure error you mentioned. 

    One of the primary advantages of the 331 is that it supports high speed sync, which allows you to use large apertures and fast shutter speeds above the normal sync speed of the camera. 

    The Yongnuo RF602 does not support TTL. You can only use it for manual exposure, which is often much easier than trying to outsmart automated metering systems. 

  11. Did you finally received the replacement triggers? Everything was OK with the new triggers? I received mine a couple of days ago and experienced a similar issue, most of the time the TR-331 is not working, but sometimes it fires.

  12. The new triggers seem to work fine and the HSS feature is useful for shooting with the lens wide open in bright conditions with the expected loss in flash output.

    For the type of shooting I do, I generally prefer the Yongnuo RF602 triggers. There are a lot of exciting new options available now but for the money they are still a great value.

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