Wednesday, February 17, 2010

Yongnuo CPR

Well, well, well... It took the demons five months to catch up with me, but find me they did. I was up at the Beargrease Dogsled Marathon two weeks ago with 4 RF-602 receivers and 2 RF-602 transmitters. The lights came on for all devices, but they simply wouldn't talk to each other. At the time, I was at BARC Net Control (Ham Radio station coordinating communications between checkpoints and HQ), so there was plenty of 2 meter traffic, and my laptop showed several wireless access points (2.4GHz is common). And yet, I couldn't get the either transmitter to work with any of the receivers. I replaced batteries, changed batteries, switched channels, etc... nothing.

The devices remained in their catatonic state even when I returned home. Last night, after they had been sitting on a shelf for almost two weeks, I got them out again. Still no love. Finally, I took the battery out of one of the transmitters, flipped the channel switches again to see if something was just off, checked the battery compartment for any obvious breaks in wiring or corrosion. Finding nothing, I popped the battery back in and gave the test button a half press and all four receivers' LEDs turned green! WTF? Sure enough, they were all talking again like one big happy family.

So, I turned my attention to TX #2. Half press of the test button and still the receivers ignored it. I took the battery out for a good thirty seconds or longer, popped it back in and Shazaam! Everyone is talking again. I still had the older batteries from Beargrease. So I popped them into the transmitters and things still worked.

Moral of the story... If things stop talking to each other, take the batteries out of the transmitters for 30 seconds or longer. I'm going to store mine without the betteries in the from now on. Yongnuo needs to add a dedicated off switch to the transmitters like they have on the receivers.

I'll give them another test this weekend to see if I can still hit over 400 feet like I did back in September.

P.S. Beargrease was a virtual Nikonfest. All the DSLRs I saw (except one) and most of the P&S were Nikon. The one DSLR exception? The Canon used by the guy from the Associated Press.

Saturday, October 3, 2009

Yongnuo RF-602... the fun continues

Here's a short little video to demonstrate how the transmitter can trigger both a flash and a second camera. The camera on the left has a transmitter that fires the flash on the left and the camera on the right. The camera on the right, has a transmitter that fires the flash on the right and the camera on the left. The camera on the left is a Nikon D80. The camera on the right is a Nikon D70s. Both cameras are set to a 2 second timer. Unfortunately, the D70s' timer resets to normal shooting mode after it fires, so we see the D80 on a 2 second delay, then fires and triggers the 2 second delay on the D70s. When the D70s shutter finally trips, it triggers another 2 second delay on the D80. Since the D70s has now reverted back to normal shooting, when the D80 shutter trips the second time, the D70s gets fired almost simultaneously. If I'd had another D80, then the cameras would have just gone back and forth until I turned one of the shutter trigger receivers off, kind of like a cheap intervalometer.

It also appears I omitted the heading for the section on using the shutter trigger and flash trigger functions at the same time. So, I added it in the original review and expanded it a little. Here is a little clarification.

Using it as both shutter and flash trigger
You can use the RF-602 as both shutter and flash trigger at the same time. However, because there is a slight delay between when the shutter signal is fired and the shutter itself actually triggers, you cannot use one transmitter to fire both the shutter and flash at the same time. To do this, you need to transmitters and at least two receivers. Place one transmitter/receiver pair on one channel and use then to trigger the shutter as described in the previous review. Put the remaining transmitter and receivers on another channel and use them to fire flashes as described in the previous review. I had no problems doing this, there was no interference between the two transmitters, and it did not affect my flash sync speed.

Monday, September 28, 2009

Yongnuo RF-602 Review
A couple of years ago - it seems longer - your choices for wireless triggers was rather limited. The so-called gold standard, the PocketWizard Plus II, provided incredible range, versatility, and reliability, but at a price tag of over $165 a unit, and you needed two units to do anything. To be fair, each unit could act as transmitter, shutter trigger receiver or flash trigger receiver, but could only fulfill one role at a time. So a few other solutions, such as Elinchrom Skyports, split the duties between a dedicated transmitter and a dedicated receiver. So you could get something that cost a little less, but had a lot less range and versatility, usually omitting the shutter trigger capability. Unfortunately, they were still outside the budget of most amaeteur photographers, a set of Skyports still costing over $200. The cheapest option, were radio triggers manufactured in China and sold on ebay. They had limited range, were of shoddy construction and questionable reliability and flash compatibility... out of the box. But with modification, one could mitigate these downsides to some extent. There have been several iterations of these triggers. Cactus V2 and V2s, RD616, a few PT-04 variations (including one that doubles as an umbrella holder), Yongnuo CTR-301 and the more recent Cactus V4. I think all of these operated on the 433MHz band and none of them workd as a shutter trigger. To make matters worse, the same companies made radio shutter triggers that operated on the same 433MHz band, and using them often interfered with the flash trigger radio signal, even when the shutter trigger and flash triggers were on different "channels".

Earlier this year, Yongnuo announced their latest trigger, the RF-602. Oddly, the units showing up on ebay were billed as shutter triggers, and were labeled for specific camera brands and models, even though the receivers obviously had a flash shoe. This caused confusion amongst the potential buyers as to what these actually were and did. There is an ongoing discussion in the flickr strobist group with well over 700 posts dedicated specifically to this new trigger. So what are these things?

About a week ago, I received two Yongnuo RF-602 sets, a 1 transmitter - 2 receiver set dedicated to the Nikon D70s/D80 (I currently own a D80) purchased from hkyongnuophotoequipment, and a 1 transmitter - 3 receiver set dedicated to Nikon D200, D300, D700 (I plan on upgrading in the near future) purchased from hk-econcept. The hkyongnuophotoequipment set came with a package containing a transmitter, a receiver, a Yongnuo brand CR2 battery, two Duracell AAA batteries, a dedicated D80/D70s trigger cable, a studio flash trigger cable (1/4" mono phono male) and a 1/4" to 1/8" phono adapter. There was a second smaller box containing another receiver and dedicated D80/D70s trigger cable. When I ordered the set from hkeconcept, I also orderes two extra PC flash sync cables. What I was supposed to receive was a kit with a transmitter, a receiver, a Yongnuo CR2 battery, two Duracell AAA batteries, a dedicated D300 shutter trigger cable, a studio flash trigger cable and a PC flash sync cable and two smaller boxes, each with two Duracel AAA batteries, a receiver, and the extra PC sync cords I ordered. I got most of that, except that the main kit was missing the PC sync cable and the two small receiver boxes were missing their respective AAA batteries. I emailed hk-econcept and they are sending the missing PC sync cable. I told them not to send the batteries. Yes I paid for them, but I have plenty. I received packages from both e-tailers on the same day. The return address was exactly the same on both of them.

The transmitters and receivers I received are all in working order. There have been a few people on flickr that have reported failures out of the box. So YMMV.

Build Quality
The first thing one notices after opening the packaging, is that the build quality is a LOT better than the ebay triggers of old. The casings of both the transmitter and receiver are plastic but sturdy. There are no gaps at the seams, and the battery door close securely. The batteries don't try to jump out while you are closing the battery door like they did with my Cactus V2s and PT-04 triggers.

The transmitter body is thicker than the Cactus V2s, but the actual height when sitting in the camera flash shoe is shorter. It is not as wide or as long as the V2s, either. There is a large trigger/test button on top of the unit. And there is a definite difference between a half press and full press, which is important when using it as a shutter trigger. On the front face (facing the subject when mounted on the camera) there is a L.E.D. and a screwlock PC port. The PC port is an input port. If you don't want to put it in your camera hot shoe, you can attach it via the PC port (if your camera has a flash sync port). I'll talk about the LED later on. On the back of the transmitter is the battery door. It has a slide and open hinge and opens easily, but is secure enough not to open by accident. The inside of the door has a raised diagram indicating the polarity of the battery and that it indeed is a CR2 3V battery. The bottom of the transmitter has a foot and a four switch channel selector allowing selection of channels 1 to 15 or ALL channels. (It's a DIP switch.) The channel selector is shipped set to channel 15 and covered with yellow film. The individual switches are recessed and quite small. You'll need a toothpick, the point of a small pocketknife or something similar to switch them. You won't be doing it with your fingers. And you won't be doing it while the transmitter is on the camera. The transmitter comes in two flavors, Canon and Nikon. The difference, is the foot. (EDIT: The hot feet really are different - a reader had told me previously that the Canon and Nikon transmitter feet were identical. The center pin is the same, but the TTL pins are configured differently between Canon and Nikon. They use different pins to send the "wake-up" signal. The receivers are identical and don't know if they are being fired by a Nikon or Canon transmitter and will send the "wake-up" signal to both the Canon and Nikon "wake-up" pins. Thus one can wake either a Canon or a Nikon strobe with the same receiver so long as the appropriate transmitter is on the camera. I've tried this with several Nikon and Canon strobes fired from both Nikon and Canon bodies.) The foot base is metal and has the additional contacts one would expect to find on a dedicated TTL flash. The only reason the TTL contacts are there are to detect when the camera is on and sense and send the ready signal to take any flashes out of standby mode. There is no lock on the foot, but it fits snugly enough on my camera that I am not worried about it sliding out in any position. (EDIT: The shoe sizes do vary from unit to unit by as much as 1.5mm in overall shoe length and up to .5mm in other dimensions, a small amount and likely within the ISO 518:2006 specification, but I don't have a copy of ISO 518:2006, so can't say for sure. While this variance did not cause any problems with the two Nikon and two Canon bodies I tested on, others with Pentax bodies have reported that shoes shoes on the small side allow enough wiggle in the shoe to cause misfires and other problems if not seated correctly.)

The receiver is practically a piece of modern art. It feels very solid in your hand. Yes its plastic, but it a very sturdy plastic. It doesn't feel like you could squeeze it and have the batteries jump out like my Cactus receivers. On the top is a 4 switch channel selector. Everything I said about the transmitter's channel selector applies. Also on top of the receiver is a nice off/on switch, a L.E.D. indicator and a hot shoe. Like the transmitter foot, the receiver's shoe comes in either Nikon or Canon flavors and looks very much like the TTL hot shoe you'd see on a camera. The on/off switch is large enough to be easily operated by anyone. It is also far enough away from the hot shoe that I had no trouble turning the receiver off/on even when a Nikon SB-800 or SB-28 was in the hot shoe. On the bottom of the receiver is a cold foot, with a 1/4-20 threaded insert so you can screw it into a flash stand or tripod, or simply slide it into a flash shoe on your strobe bracket or camera. Also on the bottom is the battery compartment. The door is quite secure and requires a little effort to slide off the receiver. However, there is no doubt in my mind that the battery door will remain in place. The two AAA batteries fit snuggly in the batter holder and stay in place even if the battery compartment door is not in place. On the back of the receiver, just below the hot shoe, /is a three-pin screw-lock port. This is where the camera-specific shutter trigger cable and PC flash sync cable attaches. The strain relief on the cables has a slightly larger diameter than the screw-lock collar, so fatter fingers may have some difficulty getting the collar started. Once the collar is screwed in place, the cable feels very secure.

Setting channels
Setting the channels is pretty straightforward. The triggers ship with the switches in the down position, channel 15. With the transmitter switches all in the up position (ALL channels), the transmitter will fire all receivers on any channel. But with the receiver switches all in the up position, the receiver can only be fired by a transmitter with the switches in the up position. Aside from that little swizzle, transmitters and receivers must be on the same channel to work together.

Using it as a shutter trigger
When using the transmitter as a shutter trigger, the LED on the transmitter turns green for a half press (focus) and red for a full press (shutter trigger). You will see the receiver LED do the same. You can hold the transmitter button in the half press or full press position for as long as you like, assuming adequate battery power, for use in bulb mode or continuous firing mode. However, it does not have a shutter lock, so in bulb mode, you can't lock the shutter open, you must hold the button on the transmitter for the entire duration.

Using it as a flash trigger
When using it as a flash trigger, it is best to put the transmitter on the camera before turning the camera on. You can attach the flash(es) using either the PC sync cable, or by putting the flash in the receiver's hot shoe. However, the wake-from-standby function only works for flashes that are mounted in the receiver hot shoe. Once the transmitter is on the camera and the receivers are turned on, when you turn the camera on, the transmitter LED turns green. Any receivers on the same channel will also turn on, so you have a visual confirmation that the transmitter and receiver(s) are communicating. When you trip the camera shutter, the LED turns red on both the transmitter and receiver. I had no problems awaking either SB-28 or SB-800 from standby. In fact, just like when you have the flash in the camera hot shoe, there is a slight delay after pressing the shutter trigger as the flash wakes from standby. So there seems to be enough smarts in the triggers not only to wake the flash from standby, but to inform the camera that there is a flash in standby as well.


So, with the above in mind, earlier today, armed with two transmitters, two receivers, two light stands, a Nikon D80, a couple of Nikon SB-28 speedlights, and a 200 foot tape measure, I set out to see what these will do.

The advertised range is 100m. Yeah, right. The range on my Cactus triggers was advertised as 30m when I purchased them 18 months ago (GI now lists them as 10m) and could barely do 30 feet without modification. So how did the RF-602's do? 368 feet with 100% reliability on the street outside my house, in a neighborhood with about half a dozen 2.4GHz wireless networks on the stretch of road where the test was performed and the Tx and Rx were line of sight. I tried another test where I tuck the Tx in the small of my back as I face the Rx/flash, so the signal has to go through me. This reduced the range to about 150 feet with 100% reliability. But moving the Tx away from the small of my back by even six inches, improved the range. So, kudos to Yongnuo for outperforming their published range. (To ensure the flash and camera were in sync, I used a telephoto lens aimed at the flash and took a picture, checking my preview screen after each test to ensure the flash was firing in the picture.)

Indoors, I could trigger a receiver placed anywhere in my house from anywhere else in my house. I could fire a receiver attached to a flash in my dining room from 300 feet outside my house.

The trigger specification indicates a sync speed of up to 1/250th of a second. My D80 has a max sync speed of 1/200th and I had no problem syncing at 1/200 at any distance less than 368 feet on any channel.... with one very special exception. More on that special exception at the end of the review.

The D80 will shoot 3 frames per second in continuous shooting mode. The triggers had no problem keeping up, even at the 1/200 sync speed. I suspect they will handle a frame or two more per scond, but that will have to wait until I get my D300.

I also tried to attach two flashes to a single Rx. I put one flash in the Rx hot shoe and attached the other flash via the PC sync cable. The Rx had no problems firing both flashes with no loss in sync speed or continuous shooting speed (frames per second). Sweet.

Using 2 transmitters trigger both shutter and flash trigger
One other thing that concerned me was the ability to use one Tx/Rx to trigger the shutter on one channel and then have a second trigger mounted on the camera to trigger one or more flashes. (No, you cannot use one trigger to trip the shutter and flashes at the same time - the flashes will fire first and the shutter will fire second because of the few milliseconds of shutter delay that every DSLR has.) When using my Cactus flash triggers in conjunction with a shutter trigger that operated on the same frequency (433 MHz), the devices interfered with each other, usually causing a delay in flash firing or complete misfire, even when the flash triggers and shutter triggers on different channels. I had no such problems with the RF-602 triggers, even with the camera and flash Tx a significant distance away and the shutter Tx right next to the flash/receiver. This is what made me look at the RF-602 in the first place. Just make sure the shutter transmitter/receiver pair are on a separate channel than flash transmitter and receivers and that NONE of them are on channel zero (switches all in the up position).

The special exception
Since, the transmitters have 15 channels to operate on, and there doesn't seem to be any interferance that causes misfires, I had the idea that perhaps you could mount a transmitter on one channel on a receiver of a different channel and rig a pseudo repeater to increase the range. So, after determining I could fire the flash reliably at 368 feet. I put the flash on a receiver on channel four. Then, 368 feet away, I set up a second light stand and mounted a receiver on channel 15 on the stand and then put the channel four transmitter in the hot shoe of the channel 15 receiver. So, the "repeater" was 368 feet away from the flash I wished to trigger. Unfortunately, the road I live on is neither straight nor level and going more than 400 feet from where the flash was set up would take me out of line of sight. So I simply started walking back towards the flash, taking pictures as I went. At about 150 feet, i could no longer get consistant reliability, largely because my thick head was between the transmitter on the camera and the "repeater" behind me. I could improve the range a little by getting my head out of the way, holding the camera to the side. This got me to 200 feet from the "repeater" on a line between the "repeater" and the flash, but not with consistant results. But if I went quite a bit off to the side, I could get up to 265 feet away from the repeater and get consistant results when I was about 175 feet from the line between the "repeater" and about 20 feet higher (I was up on a hill) than the "repeater" and flash. HOWEVER, when operating in "repeater" configuration, the sync speed dropped to 1/125 to 1/100 of a second depending on how close I was to the "repeater".

One last thing to try
I have access to a D70s. The D70s and D80 use the same shutter trigger cable. So, I want to set up one Tx/Rx to allow me to trigger the D70s from the D80 and another Tx/Rx to trigger the D80 shutter from the D70s. Then I can use the timer on one or both cameras and thus use the triggers to have a cheap intervalomoter. I'll let you know how it goes....

Other caveats...
The wake-from-standby feature does not appear to work with Pentx cameras. And you shouldn't use any flash that you wouldn't put directly on your camera's hot shoe... so low voltage strobes only.

When the RadioPopper folks first hinted at the RadioPopper Jr, they suggested a cheap, reliable, manual radio flash trigger for around $25 per unit. Yongnuo seems to have delivered on that promise with the RF-602. For the price of a single JrX transmitter and Studio receiver set, I got two transmitters, five receivers and two extra PC sync cables. The build quality of the RF-602s is very good for the price paid and far beyond the ebay triggers available only 6 months ago. Reliability was 100% at over 300 feet outside, thus I would not expect any problems working within 100 feet. The only questions is, will they still be working after a year of use and abuse? But at the price I paid, I can afford to replace the complete set on an anual basis for a couple years and still be ahead of the cost of an equivalent set of RP JrXs or Cybersyncs.