Wireless has mostly been limited to infra-red in portable flashguns, which is fine for many applications, but often falls short in terms of range and reliability. Until recently, the market for radio slaves was dominated by one brand, dedicated to RF devices, but recently flash makers began to enter the fray. How long will it be until we see RF triggering built in to pro-level Canon and Nikon portable flashguns is anyone's guess, but mine would be soon.

Nissin

For the time being, you'll have to content yourself with the capabilities of IR data communication in the better-specified flashguns. And one new model from Nissin makes a cost-effective alternative to the OE brands.

It has a high list of £369, but the Di866 generally retails at around £280, and can be compared with the likes of the much pricier Canon 580EX II and Nikon SB900, coming with some highly desirable features. It even has a few that the camera maker's flashes don't have. I didn't even notice the small secondary fill-flash until I tried taking a few bounce shots. This sub-flash tube has a guide number of 12m like a small pop-up flash on a EOS 50D or D300 body, and it's more than enough to lift shadows in portraits.

The Di866 has numerous features, but headlining must be the guide number of 60m (note that's ISO100 at 105mm, rather than more usual 35mm quoted by rivals) for the main tube, which the company described as being the world's most powerful hotshoe-mounted flashgun at the time of its launch in May.

And lets not forget the wireless flash capability. The first models to ship are Nikon fit, with Canon to follow shortly. In essence, the wireless flash capabilities pretty much mirror that of the prospective OE flash units. That's to say the Nikon-fit Di866 uses infra-red wireless control and offers both master and remote options for seamless integration with other Nikon CLS (Advanced Wireless Lighting) compatible flashguns. That makes it a close match to the Nikon SB900, and like that flashgun in master mode (Commander mode in Nikon speak), the Nissin offers a choice of iTTL control with +/-3EV compensation, or manual operation with output controllable to 1/128 power (seven steps) over four channels and three groups.

Where the Nissin differs to the Nikon unit in wireless mode is that there's no non-TTL auto flash or repeating/strobe (RPT) options. The lack of the latter means unreliable results in iTTL mode when a non-CPU (manual focus) lens is fitted. Still, the addition of the wireless modes means that Di866 fills the gap left by the now obsolete Nikon SB800 as a more affordable alternative to the Nikon pro-level flashgun.

Operation in CLS mode is for the best part the same too, so Nikon users will feel at home. To be fair though the Di866 in normal non-wireless use is even easier to operate than the Nikon SB900. It has a novel colour LCD that orientates itself between horizontal and vertical use, though it's a bit on the small side for setting some of the options.

One particular feature of note is the capability to customise exposure for personal preference, a sign of a well developed product; using the defaults, the Nissin produced a slightly lighter looking result than the SB900. Taken as a whole, the Nissin delivers a good mix of performance and features, and is a tempting buy.

Profoto

High-end Swedish lighting maker Profoto builds PocketWizard receivers into its older generators such as the Pro B2R, but its newer kit uses the proprietary Air system. Like PocketWizard Plus IIs, the Air Sync device is a no-nonsense hotshoe-mounted transceiver with two 3.5mm phone plugs, but boasts eight channels instead of four. There's no delicate external aerial, and operation is extremely straightforward - even less complicated than Plus IIs. You can pair it with another Air Sync unit for simple flash or camera triggering (or both in a relay), or the more advanced (and pricey) Air Remote.

The Air Remote has additional functionality when used with Profoto Air generators. This ranges from simple on/off operation for the unit and modelling light, to control over energy output (in one or 1/10 f-stop steps). The Air Remote also adds six groups with a master option for simultaneous control, but of course you can't use it to add this extended functionality to older packs. Both units are the same size and weight, around the equivalent of the new PocketWizard Mini TT1 unit reviewed below, thanks to the adoption of two AAA batteries.

These can be hard to find at times, and it's one of the agreeable features of the original PocketWizard Plus and Plus IIs, but the maker claims 140 hours life in transmit mode and 30 in receive. Operation is dependable, like the PocketWizards, but has two distinct advantages; one is price, and the other is the adoption of 2.4GHz radio frequency, making it suitable for worldwide use. The PocketWizards operate between 433.42-434.42Hz here and can only be used legally in Europe with the CE marking.

If you regularly travel to the States or Japan, you'll have to trade the PocketWizards in for models made specifically for those markets, or hire them locally. This gives the Air triggers a distinct advantage, and if you're using Profoto Air flash in the studio already, it's a nice bonus. In theory, operating at 2.4GHz means potential interference from Bluetooth devices and WLANs. But, the adoption of eight channels means this can be avoided, unless perhaps you're covering a large sporting or political event where that frequency could be crowded. Though even then you could take your chances against the throngs using Pocket Wizards.

PocketWizard

The name has become synonymous with radio triggers worldwide, and until recently it had the run of the market. Perhaps then that's why LPA Designs, the maker of PocketWizard, upped the game by being the first to introduce a TTL version.

Available now for Canon E-TTL II enabled cameras, with a Nikon iTTL version to follow early next year, the diminutive MiniTT1 transmitter (£210) in combination with the larger FlexTT5 transceivers (£230) with their built-in Canon-spec (five-pin) hotshoes can convey shooting data such as ISO, aperture and shutter speeds wirelessly using RF rather than infra-red. Like MultiMax and Plus IIs, the FlexTT5 has twin 3.5mm jacks for simple camera and flash triggering, and operates at 433-4Hz in Europe, theoretically up to 300m.

The range varies with flashgun, unfortunately. According to the maker, some flashguns emit high levels of RF noise, reducing the effective range to just 10m in some cases, and the newer guns such as the EX 580 II are the worst offenders. Moreover, no two Canon EX 580 II guns are the same, it claims. LPA is working on a RF shield, but it's a problem currently.

Of course the headline feature is the radio control of E-TTL II shooting data (including automatic High Speed Sync) with Canon flashguns, and these are the only products on the market to offer that capability. If you have one of the pro cameras with built-in flash control, you can use the tiny MiniTT1 to convey additional shooting info. On the 1Ds Mk III you can adjust flash exposure compensation, switch between evaluative and average E-TTL control and enable/disable flash firing, all from the camera menu (and without a flash attached).

Operation is very simple, thanks to few external controls. After setting the same channel (there are only two marked) you connect the remote flash to the Flex TT5's hotshoe, set the flash to E-TTL mode, then take a couple of test shots for the system to calibrate and you're ready. If you want to use a second flash on-camera or with a TTL cord, you can, and you can use that flash to set ratios remotely.

There are plenty of other 'hidden' features. For instance, you can trigger MultiMax and Plus IIs using their additional channels by switching the Mini and Flex over to the 'Learn' mode. And if you download the Pocket Wizard utility from its website you can theoretically upgrade both devices' firmware, should Canon alter the E-TTL specification in the future.

Another noteworthy feature available using the utility is called 'HyperSync', allowing certain camera/flash combinations to sync at up to 1/8000s at full power. It's not quite as simple as it sounds, as you have to adjust the (offset) timing of the radio-triggered flash to begin firing before the camera triggers a sync pulse, and experiment with flash durations; in this case the longer are better. Fortunately, the utility has a well-written help manual, so all that's needed is a little time experimenting with certain camera flash combinations.

All the same, if you're a Canon user frequently working with portable flash on location, covering weddings or environmental portraits for example, then the PocketWizards are an absolutely essential purchase.

Seculine

So far I've looked at two high-end RF solutions, but another recently introduced trigger from Seculine promises a recession-busting alternative in the form of the Twinlink T2D; a transmitter and receiver can be had for the price of a single Profoto Air Sync. As you might expect, the build isn't to the same level as the PocketWizards or Air twins, and they're unlikely to withstand an accidental fall to the floor, but they've a number of interesting features.

In addition to the expected infra-red triggering these are also 2.4GHz radios with 16 channels. If there's significant crowding over the 2.4Ghz band, the infra-red option could be a useful back up.

Of course, the shortcomings using infra-red are well-documented - strong ambient lighting can washout the signal and you have to maintain line of sight between to the two devices, which can be difficult when using a softbox or an umbrella. Nevertheless, having both gives you options that the others don't have.

The transmitter is a small hotshoe-mounted device with a detachable articulated aerial, and it has a 2.5mm mini-jack with a supplied PC cable for off-camera operation. The receiver has a built-in hotshoe, PC-out socket and 2.5mm jack. A coiled 2.5mm to 3.5mm cable, supplied, also comes with 3.5mm to 7.5mm phono plug adaptor for use with certain studio flash models from Bowens, Profoto, Elinchrom, Hensel, Interfit and Lastolite.

As well as supplying the three AAAs for the receiver (and two CR2030 Lithium coin cells for the transmitter), Seculine also bundles an AC adaptor for the receiver, making the kit quite a comprehensive offering. While triggering is limited to manual flash function only, operation couldn't be simpler. Push buttons cycle through the channels and backlit LCD keeps you fully informed; though the time displayed before the unit goes into sleep mode is a little confusing at first. Handily, a flash symbol indicates triggering, which is a welcome addition.

I have few real gripes. The lighting stand attachment clips over the battery-compartment, which means it has to be removed before replacing the batteries, so it would have been nice if it used 3.5mm jacks instead, but there's little here not to like. If there's a chance equipment could be damaged in use, or you're simply working to a budget, the Twinlink is certainly worthy of a closer look.