Flashguns explained
A good flashgun is one of the most essential and versatile DSLR accessories. It's not just for dark times, when you're shooting indoors or at night - a flashgun is equally useful for filling in unsightly shadows in bright, sunny-day portraits.
Unlike the pop-up flashes in most Nikon DSLRs, flashguns give you more power, greater flexibility over lighting techniques and, in some cases, advanced facilities for wireless multi-flashgun shooting.
The maximum power of a flashgun is indicated by its guide number (GN). This is usually stated for shooting at a sensitivity of ISO 100 and a focal length of 105mm. That's because most flashguns have motorised zoom heads that automatically adjust as you alter the zoom setting of your lens, or fit prime lenses of varying focal lengths.
As you stretch from wide-angle to more telephoto focal lengths, the light used to illuminate the periphery of a scene is wasted. So, by zooming the flash head, its light is concentrated on the area that will appear in the photo.
The GN enables you to know the maximum range of the flashgun at any given aperture. You simply divide the GN by the aperture you're using.
As an example, a flashgun with a GN of 40 would enable you to shoot an object from up to 10 metres away with an aperture of f/4, or from up to five metres away with an aperture of f/8. That might sound like more power than you'd ever need, but there are other factors to take into account.
Directing flash
The GN gives maximum distances only when you're aiming the flashgun directly at a target. However, one of the most essential features of any good flashgun is a bounce and swivel head.
Due to the small physical size of a flash head, direct flash produces 'hard' lighting that can be unflattering for portraits, and cause dark shadows. By tilting the flash head upwards in indoor portraiture, you can bounce the flash off a white ceiling. This effectively gives a much larger source of light, which makes for softer lighting.
The downsides of this are that the distance between the flashgun and target is increased and not all of the light is reflected, so flashguns with extra maximum power come into their own. The swivel facility does the same job when you're shooting in portrait orientation.
Working out the manual flash setting, especially when bouncing flash off walls or ceilings, can be a nightmare. Thankfully, all the flashguns in this test are fully compatible with Nikon i-TTL (intelligent Through The Lens) flash metering. This aims to ensure accurate and consistent flash power for correctly exposed images in any conditions.
A practically imperceptible burst of pre-flashes is fired to work out the correct flash exposure for the scene, just before the camera's shutter opens and the shot is taken. That's the theory, anyway, although we found the accuracy of i-TTL metering varies with different flashguns in our tests.
The zoom range of most flashguns is about 24-105mm, but this is for full-frame cameras such as the Nikon D700. However, DSLRs such as the Nikon D3100, D5100 and D7000 and D300S have a smaller APS-C sensor. With the 1.5x crop factor of these cameras, the effective zoom range translates to 16-70mm.
With many flashguns, this means that some light is wasted because there's no facility for setting them up for use on DX (APS-C) rather than FX (full-frame) cameras. It's not always the case, as the Nikon SB-700, SB-900 and recently announced SB-910 are clever enough to sense what type of DSLR they're attached to and adjust themselves to DX or FX mode automatically.
With the Metz 50 AF-1, you can make the change manually in the custom settings, although the correlation between effective focal length and flash zoom setting still doesn't display accurately between 16 and 24mm.
For ultra-wide-angle shooting, most flashguns feature a diffuser panel, which usually flips down from the top of the flash head when required.
This diffuser often shares its stowaway area with a fill‑in reflector card that can slide forward and be used to bounce flash. It's handy in portraiture, where you can use the flashgun in its vertically upright bounce mode while reflecting a little light into the subject's eyes.
Another useful feature is an AF (autofocus) assist beam. This typically fires a red coloured grid onto the target to help the camera autofocus in gloomy light.
When you're only using a small fraction of the flashgun's total available power, recycling times (the time it takes the flash to get ready to fire again) are usually short. However, there can be quite a delay after a full-power flash is fired. This can be anything from 4-22 seconds when you're using alkaline batteries.
Recycling speeds can generally be increased by using NiMH rechargeable batteries, and these are a much more cost-effective option for extended shooting sessions too.
Key flashgun features
Look out for these key features when buying a flashgun. A wider range of features will expand your shooting options.
Wide-angle diffuser
Flipping down over the front of the flash head, this diffuses the light to give a wider area of coverage. This is essential when you're using ultra wide-angle lenses.
Master/slave modes
Advanced flashguns can often be used as either master or slave units in multi-flashgun lighting setups, enabling you to get more exotic lighting effects.
AF illuminator
A patterned grid of light, usually red in colour, enables the camera's autofocus system to lock on to targets accurately, even in very dark conditions.
Bounce and swivel head
This enables you to bounce light from the flashgun off walls and ceilings for a softer lighting effect. It's most useful for portraiture.
LCD panel
For making the most of advanced settings, or for arranging custom functions, an LCD status display is an absolute necessity.
Onboard controls
These should enable simple yet effective hands-on control of flashgun settings. They're usually much quicker than camera-based menu options.
Flash stand
This lets you position your flash wherever you like while keeping your hands free, and means you don't need a bulky lighting stand.
Sunpak PF30X
Sunpak PF30X - £82/ $128
The Sunpak PF30X is larger than the Nikon SB-400 but far smaller than the other flashguns in the group. It runs on just two AA batteries and features a bounce-only head with no swivel adjustment.
Full power output is rather low, at GN 30, although there's no zoom facility in the head, so the quoted power doesn't benefit from you zooming in to match a telephoto focal length.
The control panel is basic, with no fancy features or even an LCD information panel. You can only use the Sunpak in i-TTL mode, as manual power adjustments aren't available either on the flashgun or via the camera's flash menu.
There are a couple of switches with LED confirmation for altering flash exposure compensation between +/-1.5EV, but that's it.
Performance
The i-TTL metering proved quite accurate in our tests. For more advanced use, though, the lack of manual power adjustments is a bugbear, as is the lack of swivel for bouncing flash.
The full-power recycle times of 16 and 22 seconds for NiMH and alkaline batteries are really tedious, taking up to four times longer than Nikon's SB-400.
Flash output
There's no facility to set manual flash power on the Sunpak, so it could only really be tested at maximum output, where it acquits itself fairly well.
Aperture reading at 1m
Theoretical: 30
Measured: 22
i-TTL exposure accuracy
Almost as accurate as the Nikon flashguns on teat, the Sunpak does well in terms of i-TTL accuracy, with a flash exposure of -0.3EV in this case.
iTTL exposure accuracy
Measured: -0.3EV
Colour accuracy
As is the case with i-TTL metering, there is practically nothing to separate colour accuracy between the Sunpak and the Nikon SB-400 and SB-700 flashguns.
Colour accuracy
Measured: 18
Image quality verdict
The lack of manual power settings might be frustrating for advanced users, but i-TTL metering and colour accuracy are both pretty good.
Nikon SB-400 Speedlight
Nikon SB-400 Speedlight - £125/ $195
Ideal for photographers who want to keep things simple, the Nikon SB-400 really couldn't be any easier to use. There's no LCD status panel or onboard controls, although you can still select modes such as red-eye and slow sync via the camera, or apply flash exposure compensation.
Although small, the SB-400 is nevertheless well made, with a metal mounting plate and a solid feel. In keeping with the downsized build, the flashgun runs on two AA batteries, rather than a more conventional four, and its maximum rated power of GN 30 is the joint lowest in the group, along with the Sunpak PF30X's.
Also like the Sunpak, there's a full 90 degrees of bounce, but no swivel.
Performance
Despite not having a zoom facility, or even an autofocus illumination lamp, the SB-400 does well. In both the direct and bounce modes, i-TTL metering is accurate, and manual power adjustments are available via camera menus on the latest Nikon DSLRs.
However, the reduced height puts the flash tube close to the lens, so you're more likely to need to shoot in bounce mode to avoid red-eye.
Flash output
The tiny SB-400 doesn't have a massive power output, and like the rest of the flashguns on test, it's actual output falls some way short of the claimed figure.
Aperture reading at 1m
Theoretical: 21
Measured: 32
i-TTL exposure accuracy
At -0.2EV, the SB-400 comes extremely close to a perfect flash exposure, matching the larger Nikon SB-700 and SB-900 in terms of i-TTL accuracy.
i-TTL exposure accuracy
Measured: -0.2EV
Colour accuracy
Compared with the bigger Nikon flashguns, colour balance is slightly on the warm side. However, this could be quite flattering for portrait subjects.
Colour accuracy
Measured: 11
Image quality verdict
With its small flash head positioned close to the camera, image quality is only good in bounce mode, for which the SB-400 is a bit lacking in power.
Polaroid 160 Dua Flash
Polaroid 160 Dua Flash - £160/ $249
With the popularity of video capture in DSLRs, the Polaroid 160 Dua Flash aims to cater to your every need. As well as a regular bounce and swivel flash head, a secondary LED array gives constant lighting for video shooting.
However, the LED light source replaces the conventional addition of an autofocus illuminator. Worse still, we found that the Polaroid stopped the camera's built-in AF illuminator working.
Onboard controls look and feel dated, and manual power adjustments are only available between full and 1/16 power, whereas most competing flashguns go down to 1/128.
There's also no onboard facility to adjust flash exposure compensation, which has to be done via the camera. Wireless master/slave options are lacking.
Performance
In i-TTL mode, flash exposures were often a little on the bright side in our tests, and recycling speed from full power was pedestrian.
The motorised zoom, which has a meagre range of 24-85mm on full-frame cameras, is particularly slow and noisy, and there's no ability to switch this for correct zoom settings on APS-C cameras.
Flash output
The maximum power proves quite disappointing compared with Polaroid's claims, and this continues throughout the manual flash range down to 1/16.
Aperture reading at 1m
Theoretical: 45
Measured: 22
i-TTL exposure accuracy
Uniquely in the group, the Polaroid is a little on the bright side, delivering +0.3EV flash exposures that are more likely to wash out highlights.
i-TTL exposure accuracy
Measured: +0.3EV
Colour accuracy
There's a slight blue colour cast to images. It's quite marginal, though, and rather less noticeable than that produced by the Nissin flashgun.
Colour accuracy
Measured: -2
Image quality verdict
A little too bright in most shooting conditions, when we used i-TTL flash metering the Polaroid was good in terms of colour accuracy.
Metz 50 AF-1 Digital
Metz 50 AF-1 Digital - £180/ $280
The Metz 50 AF-1 feels very robust considering its price. Bettering the company's previous model, it boasts a rugged metal (rather than plastic) mounting plate and a maximum power output of GN 50, instead of 48.
The bounce range of -7 to 90 degrees is generous, and the head swivels a full 180 degrees to the left, but only 120 degrees to the right.
A fairly typical 24-105mm motorised zoom range is available for full-frame cameras, and you can adjust the display to take the crop factor of APS-C cameras into account.
For multi-flashgun setups, there are two slave modes: one offers full wireless communication with the camera or master flashgun, while the other senses another flash via a light-sensitive cell.
Performance
The menu system is a little arcane, and not as intuitive as those on the Nikon SB-700 and SB-900. But after a bit of practice, adjustments become fairly easy.
The manual flash settings are mostly accurate, but we found practically no difference between the 1/32 and 1/64 settings. In i-TTL metering mode, the Metz often underexposed images.
Flash output
In the range between 1/4 and full output settings, the Metz is a little down on power. However, accuracy improves at lower output settings.
Aperture reading at 1m
Theoretical: 50
Measured: 32
i-TTL exposure accuracy
In i-TTL mode, images are often underexposed by a full stop (-1EV), meaning dark pictures and requiring flash exposure compensation to be dialled in.
i-TTL exposure accuracy
Measured: -1.0EV
Colour accuracy
Colour rendition is good, but we found we usually had to add positive flash exposure compensation in order to avoid colours looking quite muddy.
Colour accuracy
Measured: 16
Image quality verdict
The Metz gun often suffered from flash underexposure in i-TTL mode during our tests, making for dull-looking images. Colour accuracy is good, though.
Nissin Di866 MkII Speedlite Pro
Nissin Di866 MkII Speedlite Pro - £230/ $358
A high-end flashgun at a reasonable price, there's a lot to like about the Nissin Di866 MkII Speedlite Pro. Uniquely in this group, it has a colour LCD info panel that might sound gimmicky but makes for easy navigation of the advanced menu options.
These include variable speed repeating strobe bursts and full wireless master/slave operation with other Nikon or Nissin flashguns.
Another neat feature is that additional AA battery holders are available, speeding up the process of replacing charge.
The Nissin features a secondary, smaller fill flash strobe, too, also unmatched in the group. This is useful for supplying direct flash when you're using the main flash head in bounce or swivel mode.
Performance
Recycling speeds from full-power flashes are three seconds slower than the Nikon SB-700's when using NiMH batteries, and the Nissin takes twice as long to recycle on alkaline cells.
There's a tendency towards underexposure in i-TTL mode, and the motorised zoom is a little noisy. There's also no facility for switching from FX to DX zoom settings. Still, it's a good flashgun for the price.
Flash output
The full power output lags quite a way behind the manufacturer's stated maximum, and accuracy is disappointing at 1/2 and 1/4 settings as well.
Aperture reading at 1m
Theoretical: 60
Measured: 32
i-TTL exposure accuracy
Like the Metz, the Nissin often underexposed images when we used it in TTL mode. In this case, it's given the same -1.0EV flash exposure.
i-TTL exposure accuracy
Measured: -1.0EV
Colour accuracy
Along with dark exposures, colour balance is a little on the cool side. This makes the Nissin less than ideal for skin tones and portrait photographs.
Colour accuracy
Measured: 20
Image quality verdict
Many of our test images are too dark in i-TTL mode, and the Nissin lacks accuracy in manual mode as well. Consistent results are a challenge.
Sigma EF-610 DG Super
Sigma EF-610 DG Super - £230/ $358
Sigma's latest flashgun edges ahead of the other models on test to give the highest-rated maximum power output in the group. Like the Polaroid, it has 0-90-degree bounce and 180-degree swivel to the left, but only 90 degrees to the right.
Unlike the Polaroid, the Sigma EF-610 DG Super boasts full wireless master/slave operation for multi-flashgun setups.
Onboard controls include direct access to +/-3 stops of flash exposure compensation, as well as manual power settings, going from full to 1/64. That's a stop less than most similar flashguns, which go down to 1/128, but at least the individual increments proved accurate in our tests.
Performance
There's a lot of punch, but from full-power flashes, recycling times are a disappointing eight or 10 seconds when using NiMH or alkaline batteries respectively. The Sigma unit also often underexposed shots in our tests when we used i-TTL flash metering, so we had to resort to flash exposure compensation more than we'd have liked.
The onboard menu system is a little confusing too - we needed the manual quite a lot.
Flash output
The Sigma flash has the highest GN in the group, but power is quite lacking at the maximum setting. It also tracks fairly low throughout the manual range.
Aperture reading at 1m
Theoretical: 61
Measured: 32
i-TTL exposure accuracy
A little on the dark side, the Sigma gives us -0.7EV flash exposures. This isn't as low as the results from the Metz and Nissin, but is still rather gloomy.
i-TTL exposure accuracy
Measured: -0.7EV
Colour accuracy
The Sigma flash adds a touch of warmth to our colour rendition tests. Technically, results are poor for accuracy, but images look quite natural nevertheless.
Colour accuracy
Measured: 23
Image quality verdict
Like the Metz and Nissin guns, the Sigma unit often gives underexposed results in i-TTL mode, and colour accuracy could be better.
Nikon SB-700 Speedlight
Nikon SB-700 Speedlight - £250/ $390
With a carry pouch and a range of accessories, the Nikon SB-700 is a flashgun feast. As well as a stand for mounting the flashgun on a tripod for remote firing, you get a diffusion dome and two colour filters.
The flashgun automatically senses when the diffusion dome is fitted, locking the motorised zoom at its wide-angle setting to enable soft, even lighting. Auto-sensing also applies to the amber and green filters, adjusting White Balance for tungsten or fluorescent ambient lighting respectively.
The control panel and menu system have been overhauled from the SB-600's, and ensure intuitive operation. The SB-700 is superb for wireless multi-flashgun setups, where it can be a master or slave unit.
Performance
Maximum power is modest, at GN 37, but this is fine for general use. We liked the way the flashgun automatically converts between full-frame and APS-C cameras.
Other finery, which is shared with the more expensive SB-900 and SB910 flashguns, includes a choice of three different illumination patterns for standard, centre-weighted or 'even' corner-to-corner lighting.
Flash output
Still a little way short of the expected overall power output, the SB-700 is, nevertheless, very consistent throughout the rest of the range.
Aperture reading at 1m
Theoretical: 28
Measured: 22
i-TTL exposure accuracy
As with the other Nikon flashguns in the test group, the SB-700 proves almost impossible to fool, giving accurate results time after time.
i-TTL exposure accuracy
Measured: -0.2EV
Colour accuracy
Colour rendition is indistinguishable in shots taken using the SB-700 and SB-900. Both flashguns give natural-looking results, with neutral greys.
Colour accuracy
Measured: 9
Image quality verdict
There's practically nothing to separate image quality between the SB-700 and the fully professional SB-900, making the former a bargain.
Nikon SB-900 Speedlight
Nikon SB-900 Speedlight - £325/ $506
Nikon's pro flashgun, the SB-900 has a beefy maximum output of GN 50. It launched with exotic features such as simplified master/slave wireless operation, automatic detection for cameras with different image sensor sizes, three different lighting pattern options, and extras such as coloured filters and a diffusion dome, though these features have now trickled down to the cheaper SB‑700.
Other similarities include a thermal protection system, with a visual temperature display on the back.
However, the SB-900 adds repeating flash for a strobe effect, plus an auto-aperture mode for balanced exposures. Nikon has just announced a replacement, the SB-910.
Performance
Working seamlessly with Nikon cameras, i-TTL metering proved entirely reliable in our tests. And while the recycling speed from a full-power flash is one second slower than with the SB-700, it's still fast, at four seconds with NiMH batteries. Overall, the SB-900 is the ultimate choice for professionals, but the SB-700 is better value for amateurs.
Flash output
The SB-900 matches the Metz for outright power, and it proves really consistent throughout the whole range, right down to 1/64 power.
Aperture reading at 1m
Theoretical: 34
Measured: 32
i-TTL exposure accuracy
You'd expect supreme accuracy from Nikon's top professional flashgun, and that's what you get, although it's matched by the SB-400 and SB-700.
i-TTL exposure accuracy
Measured: -0.2EV
Colour accuracy
The fantastic power ouput of Nikon's biggest flashgun is matched by good performance in our colour accuracy tests across the spectrum.
Colour accuracy
Measured: 18
Image quality verdict
For accuracy in both manual and i-TTL modes, the SB-900 is a standout performer, and colour accuracy is impressive. It's the top pro choice.
Verdict: best flashgun for Nikon cameras
Compared with the outdated Nikon SB-600, the new Nikon SB-700 is a big leap forward. A key feature is auto-sensing for FX/DX-format cameras, the motorised zoom and focal length display being automatically switched accordingly.
Auto-sensing is also on hand for use with the amber and green filters supplied, as well as the diffusion dome. What's more, advanced features are instantly accessible from a brilliantly simple and intuitive onboard control system. These extras include fully wireless master/slave operation for multiple flashgun setups, plus three alternative lighting patterns
The Nikon SB-900 adds greater maximum power and extra flash modes. For most of us, though, the SB-700 is more than capable enough for practically any shooting scenario.
Meanwhile, the Nissin Di866 MkII is a similarly full-featured flashgun, with neat extras such as a secondary fill-flash tube and colour LCD info panel. It's good value, but recycling speeds were slower than on Nikon's flashguns, and it frequently suffered from underexposure in i-TTL mode.
The similarly high-spec Sigma EF-610 DG Super and less advanced Metz 50 AF-1 also tended towards underexposure.
The Polaroid 160 Dua Flash was less impressive. Substituting the AF assist beam for an LED array giving continuous lighting might sound like a good idea for video shooting. Ultimately, though, it's quite a basic flashgun.
The smaller Sunpak PF30X lacks even basic onboard controls and has no facility for adjusting manual power settings. The Nikon SB-400 is a better option if compactness is top of your wish list.
Verdict
The Nikon Speedlight SB-700 gives consistent results you can count on, and is an absolute joy to use.
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