willaim wrote:
Looking for a flash for my 80D and I saw that B&H is selling a Yongnuo Speedlite(YN600ext-rt) for canon. Maybe I am behind the times, but I never heard of Yongnuo. Does anyone know or have information about this flash. Price seems right as I am on a fixed income.
I shoot with Canon and have stuck with the Canon flashes. A lot of people use Yongnuo, though, and seem relatively happy with them.
Compare any you are considering side-by-side with the most similar Canon flash. That should help, since the Canon flash are pretty full featured, easy to use and powerful.
Canon "RT" are radio triggered. This is used for wireless off-camera flash work. To use it, you need both an RT transmitter and an RT receiver. This supports most flash functions, even when off camera and up to 100 feet away, even around corners or with the flash hidden behind something. Generally speaking, direct line-of-sight from transmitter and receiver is not necessary (though distance may be reduced by objects).
Most other Canon flash also can be used off-camera wirelessly, but they use optical triggering and communication. Similarly, most flash functions are possible. However, generally speaking the distances possible are a lot less... about 35 feet or less, depending upon ambient light conditions... and direct line-of-sight is needed, limiting where you can place the flashes in relation to the transmitter.
The RT or optical "transmitter" can be another Canon flash or a flash triggering module (such as the ST-E3-RT or ST-E2). Some Canon DSLRs also can wirelessly control off-camera flash, using the camera's built-in pop-up flash. This is similar to the optical triggering mentioned above, except that it has less range and uses rapid, white-light strobing of the built-in flash to communicate, which can be a bit obnoxious.
I don't know if Yongnuo can work wirelessly in exactly the same way. Likely they can do much the same via the optical triggering and communication... but not the radio triggering (which is probably proprietary to Canon).
Canon currently offers three RT devices... the top-of-the-line 600EX-RT, slightly more compact 430EX-RT and the ST-E3-RT controller module.
Canon flash that can act as "Master" and control another off-camera are basically limited to two models: the top-of-the line models (600EX, 600EX-RT, 580EX II, etc.) and the smallest of all: the 90EX (no RT version yet). And, of course, there also are the relatively compact ST modules, for the same purpose. Nearly all Canon flash can act as off-camera "Slaves".
As someone else already mentioned, the top-of-the-line models also have option to use an external power supply. 600EX, 580EX II, 580EX, 550EX.... all have a socket near the base for power connection. Canon makes their own Compact Battery Packs, that use eight additional AAs and work fine to allow much longer shooting sessions and speed up flash recycling to some degree. Current model is CP-E4, but in addition I have and use CP-E3 and CP-E2... they are largely interchangeable, backward and forward compatible with all the the top-of-the-line EZ flashes. There are also third party power sources that can be connected to the flash.
All lower models of Canon flash cannot be used with Canon's Compact Battery Packs. Those flashes do not have the connecting socket. However, some of the third party power sources will work with 430EX, 420EX, 380EX, etc... BUT, some modification of the flash is necessary. You have to cut a hole in the battery compartment cover, for the power cable connected to the external power pack.
When comparing them with Yongnuo, in addition to off-camera control most Canon flash are pretty full-featured and powerful for their size. They all have ETTL, essentially auto exposure control with flash. This is done by firing a lower powered "pre-flash" and measuring it with the camera's meter, to calculate what fuller power output is needed. The fuller power flash is then fired. This is usually done so quickly you might not even notice that the flash fires twice. Almost certainly Yongnuo will work the same way. The last couple generations of Canon flash and cameras have ETTL II, which is slightly more advanced, doing the same as the original version, but also taking into consideration distance information that's gotten from the lens and focusing system. Many of the more recent Canon DSLRs also have menus to make many or most flash settings with the camera, rather than on the flash itself.
Most will do High Speed Sync (HSS) which allows you to use shutter speeds faster than the camera's flash sync speed, although it limits the flash's reach considerably. And, with most models you can set Rear Curtain Sync (though not at the same time as HSS). In case you're unaware, this can be handy when shooting moving subjects with flash.
Many Canon flash have means of setting Flash Exposure Compensation (FEC)... which serves the same purpose as standard Exposure Compensation when not using flash. REC can be set directly on several of the higher end models, but it also can be set via the camera on most (maybe all) Canon flash models.
There's more, such as high speed strobe effects.... but the flash's Guide Number (peak power) and the above key features I'd compare if considering a third party flash.
I'd also highly recommend a flash bracket of some sort... in order to position the flash farther from the lens and a little higher, to reduce redeye and shadow effects. Canon doesn't make flash brackets, but there are a wide variety of them available (I keep it simple with a couple fairly generic, cheap brackets). To use a flash bracket, you'll also need an Off Camera Shoe Cord to connect the flash to the camera's hot shoe. Canon does make OCSC and they work fine. There are also third party OCSC that are about 1/3 the cost and probably almost as good, should work the same... after all it's just a bundle of wires with hot shoe connectors on each end.
The only problem I've ever had with any of my Canon flash and accessories have been hot shoe on OCSC or the foot on the flash loosening a little. It was just a matter of removing the screws one at a time, putting a small dab of blue Locktite on it, then re-installing the screw and tightening it. Never had any problems since. Some of my Canon flashes I've been using for close to fifteen years. I will eventually convert from the earlier optically triggered ones to the newer RT models, simply because off-camera radio triggering is more flexible.
One thing that's missing from the ST-E3-RT is that it doesn't have a Focus Assist feature, like the older optically triggered ST-E2 does (most of the flashes have it, too). Focus Assist projects a near IR grid to help the camera and lens focus in low light conditions. Even though this is relatively limited in range (about 15 feet), I've found it useful even when not using flash. So, if and when I switch to the RT flashes and controller module, I'll likely keep my ST-E2 just to have Focus Assist. (Note: The RT flashes can do Focus Assist... it's only the ST-E3-RT module that can't.)
I know you are looking at Yongnuo flash, instead of Canon... but hopefully the above will help you compare and be sure the third party flashes can do all that you need them to do.
EDIT: Just checked out the YN-600EX-RT on Amazon and it looks pretty impressive. I see they also have a neat YN-E3-RT controller module. And, Yongnuo has something Canon doesn't offer... a receiver (YN-E3-RX) that appears to make possible full radio control of the earlier 580EX, etc. models. Works with their controller module. I'll have to study the Yongnuo RT stuff more closely.... looks like an interesting alternative!