Viltrox Spark Z3 review: a ‘mech-inspired’ compact flash with Auto TTL metering

I’ve been highly impressed with Viltrox lenses for Fujifilm X, Nikon Z, and Sony Alpha mirrorless cameras over the last couple of years, ranging from unfeasibly compact, lightweight, and affordable ‘Air’ series lenses to top-notch ‘Pro’ and ‘Lab’ lenses. While the company majors in lens design and manufacture, it also produces camera monitors, photographic lights, and lens adapters.

Viltrox has recently branched out into on-camera flash units, and I was quick to snap up a Viltrox Vintage Z1 Retro Flash, which I reviewed recently. I liked that it had a pretty much universal fit, suitable for any camera with a central firing pin in its hot-shoe, but the flipside is that without a dedicated design, auto TTL (Through The Lens) flash metering is off the menu. You therefore have no other option than to dial in the flash power setting manually. The Spark Z3 that I’m reviewing here goes the other way, being available (so far) in Fujifilm, Nikon, and Sony dedicated options, all with Auto TTL flash metering in addition to manual settings. Let’s see what it has to offer.

Viltrox Spark Z3: Specifications

Viltrox Spark Z3: Price

Own-brand flashguns from camera manufacturers tend to be pretty pricey, even for fairly entry-level models like the Canon Speedlite EL-10 at $219 / £280 / AU$350 and the Nikon SB-700 Speedlight at $418 / £310 / AU$450. Third-party alternatives tend to offer much better value, one of my favorites being the relatively powerful and feature-rich Godox Ving V860-III at $229 / £175 / AU$350. However, all of these are full-sized flashguns. 

The Godox Spark V3 is much more compact and lightweight, and relatively basic, although it does include Auto TTL flash metering. I reckon the early prices popping up around the Internet of $79 / £66 / AU$119 make it potentially great value for money. For comparison, the fully manual and less powerful Viltrox Vintage Z1 Retro Flash costs around $50 / £48 / AU$76.

Viltrox Spark Z3: Design & Handling

I used to be able to guess what a flashgun would look like before even seeing it, and I’d be right pretty much every time. I’m guessing you’re the same. But a couple of recent retro styled flashes have taken me by surprise, and in a good way. The first one was the Godox iA32 and the other was the Viltrox Vintage Z1 Retro Flash. The Godox isn’t as basic as it looks at first sight, as it has auto flash metering (not TTL) and an internal bounce facility with an operating knob on the side. The Viltrox is a purely manual flash but looks just the ticket on retro-styled mirrorless cameras, and both models feature dual optical slave modes – more on that later.

The Viltrox Spark Z3 that I’m reviewing here looks and feels very different to both of the above. Let’s start with its looks. It’s styled differently to any other flashgun that I can think of, with what Viltrox calls ‘a mech-inspired design with visible photon core.' To my mind, it has a sci-fi look to it that wouldn’t be out of place on a film set. And that’s not all. The ‘visible photon core’ refers to a transparent section of the top cover so that you can see the electronic components laid out on their circuit board beneath. All very trick!

More than just tech-mech style over substance, the Z3 currently comes in three dedicated versions to suit Fujifilm, Nikon and Sony cameras, with rumors of a Canon dedicated version to follow. The key advantage is that automatic flash metering works ‘through the lens’. As such, when in automatic mode, the Z3 fires pre-flash pulses, which the host camera registers through its lens and works out the appropriate power setting accordingly. That’s all well and good but I often find that the theoretically ‘correct’ flash exposure that automatic TTL flash gives me isn’t what I want in practice, so auto flash exposure compensation is often required. Digital cameras beat analog film cameras hands down in this respect, as you can simply review images as you’re shooting and adjust the flash power as necessary.

In fact, after many years of trying to rely on TTL flash metering and being disappointed along the way, I tend to favor manual power settings most of the time nowadays. The Z3 again obliges with a simple Auto/Off/Manual knob on its rear panel. When the flashgun is turned off and you power it up, you can therefore simply turn the knob to the left for Auto TTL mode or to the right for Manual power settings.

While the transparent section of the top cover gives you something interesting to look at, there’s no LCD info screen, which would arguably be of greater use. There aren’t even any indicator lamps for power settings. Indeed, TTL flash exposure compensation needs to be set by using the menu system of the host camera, rather than directly on the flashgun. And for power adjustments in Manual mode, there’s a rotary knob just next to the Auto/Off/Flash knob. Instead of a rank of indicator lamps, which are often featured in flashguns that lack an LCD display, the knob simply has power values printed on it, comprising 1/64, 1/32, 1/16, 1/8, 1/4, 1/2 and 1/1 settings. As such, you can set anything from minimum to maximum power, nominally in full EV steps. That might well leave you wanting finer, intermediate settings and indeed, most flashguns enable you to adjust the power in much smaller increments of 1/3^rd EV steps.

Fancy a little something on the side? A switch on one side of the casing hints at the Z3 having another trick under its see-through hood, in the shape of dual optical slave modes. Sure, it doesn’t have the luxury or range of RF (Radio Frequency) wireless communication, but you can set the flash to be triggered by a master flashgun in a multi-unit setup. Moreover, the two operating modes enable the Z3 to be triggered by a main flash in Auto TTL or manual mode, the latter also catering to studio flash heads as it ignores any pre-flash pulses.

One thing that’s lacking in the Z3 is a bounce and swivel head, although that’s not surprising given the compact and lightweight form factor. Even so, it can be a bit of a blow if you like bouncing flash off a ceiling or wall for a softer lighting effect. On the plus side, the Z3 is supplied complete with a white diffusion panel that you can clip onto the front. This not only softens the quality of light but also gives more wide-angle coverage.

Viltrox Spark Z3: Performance

The time-honored tradition is for flashguns to run on either two or more commonly four AA batteries. More recently, that’s given way to flashguns featuring rechargeable Li-ion batteries, either as a clip-in battery pack or an internal battery. The Z3 backs up its futuristic looking design with an internal 3.7V, 1800mAh Li-ion battery. Typical advantages over AA batteries are faster recycle speeds after high-power flashes, and greater stamina in terms of the total number of flashes you can get before you need to change or recharge the batteries. In this case, the internal battery can deliver 650 full power flashes (very many more at lower power settings), after which it takes about 70 minutes to recharge, via the Z3’s USB-C charging port.

I think the number of full-power flashes per charge is very impressive, considering that the maximum output is a pretty meaty 26Ws, equating to a claimed Guide number of Gn 16 / 52.5 (ISO 100, m / ft). The maximum output itself is rated a lot higher than the pop-up flash of most cameras. For example, that of the Nikon Z50II is rated at Gn 5.6 / 18. Either way, the Z3 actually delivered a maximum power equivalent to Gn 11 / 36.1 in my tests, one stop less than the claimed figure. On the plus side, the full step EV adjustments in manual power settings proved accurate in my tests, from full power down to 1/8^th, although they were less consistent in the lowest part of the range between 1/4 down to the minimum of 1/64^th.

I did miss being able to adjust the manual power setting in finer increments than full EV steps. The following gallery demonstrates the minimum available adjustments. The first shot in the sequence has what I feel is the correct flash exposure, at a power setting of 1/16^th. For the second shot, flash power was decreased by as little as possible to 1/32^nd and for the third it was increased by the minimum amount to 1/8^th. I could have done with some finer incremental adjustments.

Image 1 of 3

When it comes to recycle speeds, Viltrox claims a super-fast time of just 1 second after a full-power flash, before the Z3 is ready to fire again. In my tests, the Z3 lived up to these claims and as I’d expect, recycle speeds after low-power flashes are virtually instantaneous.

I tested the Nikon-dedicated version of the Z3, using my Nikon Z6 II and Nikon Z fc cameras, plus my old Nikon D7100 DSLR. I found that Auto TTL flash metering gave me consistently ‘correct’ exposures when using a number of different lenses and shooting various subject matter over different distances. The accuracy was borne out when taking test shots of a grey card and checking the histograms of the resulting images.

The quality of light from the Z3 proved very good and with a manual white balance setting, the color temperature was very consistent over the whole power range. With my Nikon-dedicated version of the Z3, I found that a wide range of flash modes was available through the camera’s menu system, although high-speed sync is not supported so you’re limited to the regular sync speed of the host camera body. That can be a bit of a pain when using flash to fill in shadows during sunny day portraiture.

The diffuser panel is of value for softening the light a little although, with no bounce or swivel modes being available, it has little effect on dark shadows. The following pair of shots was taken of some flowers in a vase from slightly above, with and without the diffuser panel fitted. The diffuser does soften the light and reduce the hardness of shadows but those shadows are still very deep.

Image 1 of 2

I found the optical slave options worked well with good reliability, in both available modes. S1 mode is for use with a master flashgun in TTL mode, S2 when there are no pre-flash pulses. Either way, you can only use the Z3 as a slave flash in Manual power mode settings.

Viltrox Spark Z3: Lab Results

We test all available features for each flashgun that goes through out labs. To test power output, we used a Sekonic flash meter placed at a distance of one meter from each flashgun. We check the complete range of manual power settings, in one-stop increments. Based on a sensitivity of ISO 100, the figures correlate directly with the Gn (Guide number) in meters. The results are double-checked by taking shots of a gray card with the appropriate lens apertures and using the camera’s histogram display in playback mode.

We also check the speed with which each flashgun can recycle to a state of readiness, throughout its range of power settings, culminating in a full-power flash. We use freshly charged Ni-MH rechargeable batteries for this, or the supplied rechargeable Li-ion battery pack where featured in some flashguns.

The table below shows both the power output (Gn, ISO 100, meters) at each full EV step through the complete power range, from minimum to maximum output. The recycle speed in seconds is shown for the same settings.

Viltrox Spark Z3: Verdict

Many modern mirrorless cameras don’t feature a pop-up flash, all three of mine included. I like that the Viltrox Spark Z3 stands in admirably for this omission, being small enough to fit in a spare coat pocket yet slipping into a hot-shoe and delivering a sizeable chunk of power, surpassing that of any pop-up flash I’ve ever used in my older cameras. The Auto TTL metering is reliable and proved consistently accurate in my tests. Manual power output is quick and easy to adjust, although I wish there were finer increments on tap, rather than just full EV step changes. The ‘mech-inspired’ design is a matter of taste but I rather like it, and the supplied diffusion dome is a nice add-on. All in all, the Z3 is a really handy little flash and great value at the price.

Alternatives

The Viltrox Vintage Z1 Retro Flash doesn’t have an Auto flash metering facility so you have to set the output power manually. Even so, it’s a very simple flash to use and works very well, either in your camera’s hot-shoe or in dual optical slave modes.

The Godox iA32 has rather charming retro styling and Auto flash metering based on a light-sensitive cell rather than TTL metering. It also has an internal bounce facility that you can operate via a knob on the side, which is a nice touch.