No AA's? No problem! Late last year Neewer, a company previously bashed for making fake MB-D11 battery grips, released the TT850 speedlight (you may also find this same flash branded as the Godox Ving V850). While not offered by B&H, they can be found on eBay and Amazon, for around $100. Typically I wouldn't get too excited about a third party product but there is a particular feature that sets the TT850 apart from its competitors and put it at the top of my list. This little guy is not powered by the traditional AA batteries found in (to my knowledge) every other speedlight, rather it uses a beefy, 12-AA-equivilant lithium ion rechargeable battery with a maximum output of 650 pops at 1/1 power.
As a lifestyle and editorial photographer I tend to avoid strobes and speedlights altogether in favor of natural light, reflectors, and hot lights. I only reach for my strobes when I'm in need of punchy, well defined light in a small package or some portable on/off camera light. My experience thus far with the TT850 has been rather impressive, it has honestly changed the way I look at speedlights and will likely be joined by another in my bag soon.
The TT850 is roughly the same size and weight as the Nikon and Canon flagship speedlights. Even though the TT850 is by no means a featherweight, there is a noticeable difference in build between the Neewer and the 5x more expensive Nikon SB900. This difference shouldn't be too pronounced unless you're holding one next to the other and certainly isn't a cause for concern. At the end of the day if your TT850 snaps in half you still have enough money left to buy 4 replacements compared to the high-end manufacturer models. The buttons, switch, and wheel on the TT850 feel durable. The mount is made of metal and locks securely in place with a pin just like the Nikon and Canon models. I do miss the easy to use switch-style locking of the newer Nikon speedlights, but have no major complaints in this department.
When using 2,000 mAh eneloop batteries in a SB900 I get a maximum of 200 cycles. While you can get up to 250 cycles with lithium AA's towards the end the time between cycles gets unreasonably long. In this respect, the TT850 blows its competitors out of the water. The manufacturer advertises 650 pops at 1/1 and in my experience I've never run a shoot where I needed to replace the battery. While I'm by no means a machine-gunner with my shoots the cycle time hasn't been a concern either. There is one (rather noteworthy) holdup with respect to the battery life — the TT850 does not have a port for an external battery packs that wedding and event photographers are so fond of. The lack of external battery options might or might not be a deal breaker for you, some people will find that 650 cycles is more than enough (and given the size and price of extra batteries) might not be opposed to simply carrying an extra battery or two for more intensive shoots.
Having compared the TT850 output to the Nikon SB900 at fixed camera and flash settings I've found that there is no real difference in power, coverage, or duration to the light output. Judging by other video reviews the TT850 output appears to be on par with it's competition with equivalent or marginally better brightness and balance. When shooting outside, if you intend to overpower the sun I'd still recommend using two or more in a softbox to avoid the bare-bulb look. Otherwise, these make tremendous fill or rim lighting solutions.
The TT850 is a manual flash, meaning that settings such as power and zoom must be manually adjusted on the speedlight, no TTL here. This should not be a problem for shooters who already are using their equipment in "M". If, however, you use "P" (as in professional) or aperture priority this might be a stumbling block. From my experience, using and adjusting the TT850 is simple and rather painless. Button placement is as it should be; the controls are intuitive. There should be relatively little learning curve (even less if you're willing to spend some quality time with the instruction booklet). The only U/I issue I've run into is that the beep setting does not remain activated after turning it off and back on. That said, the cycle time is fast enough that I really didn't need the beep! My only real gripe is that the LCD backlight doesn't seem to stay on as long as I'd like.
The lithium-ion battery of the TT850 allows for a remarkable cycle speed of 1.5 seconds at maximum power. While I didn't break out the stopwatch, this figure appeared to remain fairly consistent throughout the battery life of the flash. In contrast, the SB900 requires a minimum of 2 seconds to refresh and only gets worse as the battery drains. The flash has no problem syncing with the sluggish 1/200th of my Nikon D610 and can sync up to 1/8000th of a second on some Canon models with their "Cells II" transmitter, not too shabby.
The TT850, being a center-pin manual flash works on all cameras with a standard hotshoe, Nikon, Canon, Pentax, (now even) Sony. If fired off camera you have even more options, the TT850 can be triggered as a slave (in response to another flash firing), or by using the surprisingly useful Neewer 16-channel wireless transmitter (sold for around $30). This transmitter fits on the hotshoe of the camera and has a adapter that plugs in to the side of the flash and can be used to trigger the TT850 up to 1/250th as well as control power remotely. It's not a Pocket Wizard, but for the price it's not bad. As previously mentioned, Neewer also makes a transmitter called "Cells II" which allows some cameras to sync the flash up to 1/8000th of a second. It should be noted that the TT850 does not have a standard 3.5mm sync plug for Pocket Wizards. An adapter can be purchased for use with other — non-Neewer — transmitters. Again, this might or might not be an issue for you.
Despite the eccentricities that inevitably come with third-party products such as the missing external power plug, and odd sync port I have been thrilled with the performance of this dark horse speedlight.
What I like:
Rechargeable battery - The rechargeable lithium-ion battery is a unique and very useful feature that allows me to carry 12 fewer AA batteries or a large external power pack while still producing upwards of 650 1/1 power pops and a crazy fast recycle time of 1.5seconds.
Simple U/I - The interface of the TT850 is great and makes transitioning from a Nikon or Canon speedlight or working with one of each a breeze.
Price - At around $100 for the strobe, Neewer is practically giving it away. Considering the power and performance of the TT850 this price is very reasonable. If given the choice between one SB900 and a fleet of 4 TT850s I'd definitely go for these plus a handful of the transmitters.
What could be improved:
TTL - While I typically shoot in "M", event and wedding photographers will probably miss the flexibility of an automatic flash. However, if you have time to fiddle with settings this shouldn't get in your way.
No 3.5mm outlet - Want to use the TT850 with your Pocket Wizards? Sorry. You're going to need an adapter.
No external power options - If you're planning on shooting 1,000 1/1 shots in a day you're going to be disapointed in the lack of external power outlet on the TT850. Though the battery should provide 650 pops, so it may be easier just to purchase a spare and keep it in your pocket.
If you're a shooter comfortable with adjusting settings in manual or have the time and patience to experiment a little this little speedlight is for you. For $130 I was able to purchase the speedlight and proprietary wireless transmitter, a fraction the cost of even the entry Nikon and Canon flashes. The TT850 has set the bar very high for its competitors, I hope to see Nikon release a lithium-ion powered competitor soon.