I have recently got interested in off-camera flash photography and have purchased Canon 430EX II along with Yongnuo rf-603 transceivers.
Now I want to extend it with 2 light setup for more creative and dramatic lighting. I was wondering which Yongnuo flash will be good to team up with my 430 EX II.
P.S. I use Canon 550D
It depends what you want to do.
If you never envision yourself using TTL control, then just about anything will do (though you might find the YN462 to be way underpowered compared to the other units in the lineup). For the sake of versatility, you might want to stick to the higher-powered units (either "mark" of the YN560) just to make sure you have power to spare when using modifiers (umbrellas, softboxes, and so forth). The YN460 is also a good choice, but with less power (Photoflex and others sell the YN460II rebranded in North America for about $150 or so, which is a bit of a vote of confidence). Note that the colour has been reported as being a little bit bluer than average for a flash, but that's fixable with a 1/8- or 1/4-cut CTO gel (about six or seven bucks for a 20x24" sheet that'll last you the better part of a lifetime) so getting it to work with the Canon is not going to be a big problem.
If you even think you might want to try TTL shooting at some point (and there's much to be said for TTL), then the YN565EX (for Canon) is probably what you want. It will take orders from the Canon flashes (although the Canon flashes won't take orders from it). It will function as an E-TTL flash on camera or with a remote cable. And it still has all of the manual functions of the all-manual 460&560 models and power similar to the 560. The only drawback, really, is the price; although it is a far sight cheaper that a Canon-branded flash, at an eBay price of around $150, it is quite a bit more expensive than the all-manual models.
I'm using YN460 + Canon 580EX II and I like YN460 a lot, because it's simple to use and it's very powerful and the price is affordable.
I shoot off camera flash all the time and use the YN560. A friends has the YN560 Mark2 with led read out. This is all we use even though we have Canon 580 flash since we are shooting manual flash. We use the rf602 triggers and rarely have any fails. When shooting off camera flash, the more powerful flash the better.
Some time since original post, I notice, but for anyone else interested: check out the Yongnuo YN 500 EX, it's a relatively new model and from what I can tell it's quite heavily "inspired" by the 430 EX II. I have one personally and I'm very happy with it.
Plenty results from a google search, here's one of them:
http://thephotogadget.com/products/yongnuo-yn500ex-yn-500ex-wireless-high-speed-sync-ttl-flash-canon
If you plan on sticking with the RF-603 triggers the YN-560III/YN-560IV is the best purchase, since those come with a built-in receiver for that trigger. However, they pair better with a YN-560-TX transmitter unit, because the TX can also let you control the power level on the YN-560III/IV remotely from the camera. But can't control the power on your 430EXII, although it can fire it if it's on an RF-603.
If you're okay with spending a bit more on triggers, however, then a better pair for the 430EXII would be one of the Yongnuo TTL EX models, and bumping up to the YN-622C triggers. This way, you'd have full TTL, HSS, wireless 2nd curtain, and remote power control of both the flashes from the camera. Most off-camera flash aficionados will tell you you don't need eTTL (too much Strobist brainwashing) and you don't for studio-type lighting setups, but it's much more convenient to have remote power control and HSS and the communication that allows that either has to be built into a flash/trigger pairing, or done through the TTL (i.e., non-sync) pin signals.
Of the three EX models you might want to consider--at the time of this writing--the YN-565EX (and MkII), YN-568EX (and MkII), and YN-500EX are probably the three most popular. The 565 and 568 both have the same power output--roughly between a 430EX and a 580EX, but only the 568 has 360 degree swivel and HSS, and only the 565 has a battery pack port. The 500 has 1/2 stop less power (so, say, roughly equivalent to a 430EX), HSS, no battery pack port, and only 270-degree swivel. However, Yongnuo models proliferate like rabbits, so check with the Flash Havoc blog to see what the latest developments are before buying.
