Sigma EF-500 DG ST Review

Sigma are best known for producing lenses for SLR cameras, but less known for their flashguns. The EF-500 DG is their entry-level dedicated flash in an arena where the words Speedlight and Speedlite are king.

We trialled the EF-500 DG on a Pentax system, but there are also versions for Sigma, Canon, Nikon and Sony (Konica Minolta) cameras. Each version offers dedication via pins on the flashgun's hot-shoe and compete against some strong products from the camera manufacturers. As with Sigma lenses, you have a price saving by buying this independent option - the RRP of the EF-500 DG is £100, while similar guns from Canon, Nikon or Sony are around £70-£100 more.

Sigma EF-500 DG ST specifications

• Guide number: 50 at 105mm (ISO100/metres)
• Power source: 4x AA Alkaline or 4x NiMH batteries
• Charge time: Approx. 6seconds (when using alkaline batteries) Approx 4seconds (when using NiMH batteries)
• Number of flashes: Approx. 220 flashes (when using alkaline batteries) Approx. 100 flashes (when using 4x NiMH batteries)
• Flash Duration: Approx. 1/700 seconds
• Projection Angle of the Light: Automatically set to match the lens between 28mm and 105mm. Also covers 17mm wide angle when used with the built-in diffuser.
• AF Auxiliary lamp: Red LED
• Bounce: Up 60, 75, 90 Down 7
• Swivel: Right 60, 70, 90deg Left 60, 75, 90, 120, 150, 180
• Dimensions: 77x139x117mm (W x H x L)
• Weight: 320g
• Compatible Cameras: Sigma SA, Canon AF, Minolta AF, Nikon AF, Pentax AF

Sigma EF-500 DG ST modes and features
On first glance the Sigma EF-500 DG ST flashgun has all the obvious features, such as a zoom and swivel head, a test button and an AF focusing assist panel. Look a bit deeper and you'll find a guide number of 50 when the flash is set to a 105mm focal length (at ISO100). The angle of the flash is set automatically to match the lens’ focal length and ranges from 28mm wide-angle to 105mm medium-telephoto. It incorporates a wide panel that slides out from the tube to expand the angle of illumination and cover a 17mm focal length lens.

The rear panel offers just a few control options. You can switch from off to TTL or manual with full power or 1/16 power options. The 1/16 power setting is ideal for close up shooting and this, along with the 7 degree down tilt on the head, means macro photographers are well catered for. The test button is next to a flash ready light and the focal length scale above lights up to indicate the angle selected.

As well as a downward tilt the head can be raised to point up at 90 degrees and also has a locking position of 60 and 75 degrees. The lock button is on the right and is depressed to release the head. To swivel through 270degrees you depress a different button on the back.

The Sigma EF-500 DG ST has the usual hot shoe mount with necessary dedicated pins, depending on camera model*, and a rotating lock to ensure a secure fit on the camera accessory shoe.

*You can see which features are on offer for each of the camera systems here

The battery compartment can be misaligned	Dedicated pins offer exposure control via camera

Sigma EF-500 DG ST build and handling
The Sigma EF-500 DG ST looks solid and the handling is backed up by this. It has a substancial feel in mottled plastic that gives it a sheen. The lock buttons for release of the head rotate and swivel are positive, but it's a shame they cannot be done in one action. Both direction movements are smooth with positive clicks.

Inserting batteries is simple. A direction icon appears on the lid and is easy to see. The plastic cover can move out of alignment so you have to be careful you don't press down at an angle when closing or you may break it. The hinge could be improved.

The on/off switch is inset so you cannot accidentally catch it, but it helps if you have finger nails to move it. If you leave the gun switched on and unused for more than a few minutes it powers off to save batteries. It can be kicked back into life by pressing the test button once.

Having a built in wide-angle panel is a good move and it's easy to get at. The spring hinge looks flimsy though and any heavy handed use may result in this breaking.

The lock for the hot shoe gives a firm grip so the dedication pins have no chance of slipping out of alignment.

When not in use the head can be set at 90 degrees and stored in one of the sections of a gadget bag.

Sigma EF-500 DG ST performance
The reason most people buy a hot shoe flash is to extend the distance that you can cover indoors over and above the range provided by a built-in flash, but many portrait photographers are taking flash outdoors, like the pros/press, to add fill-in, even on bright days. And landscape snappers find a bit of flash to spark up the foreground works a treat.

So the Sigma, boasting a guide number of 50, should be ideal. Well, it's actually a bit of a lie. It's only 50 at the 105mm setting. The true guide number is 40 at the 50mm setting, and if you think this is going to offer power similar to a Metz 45 CL think again. The Metz guide number is based on a 35mm setting which takes the Sigma down to a GN of 35. That said it's still a fairly powerful gun and gives good range, especially if you're shooting at wider settings. F/4, for example, will illuminate a subject about 10 metres away at ISO100.

I tried the flash on a Pentax K10D with a 16-45mm zoom attached. My first attempts were outdoor shots in TTL mode. I set the camera to manual to avoid the flash forcing the high flash sync speed and metered for the middle distance. The idea was that the flash would light up the foreground. I had an aperture of f/9 and the results in some cases were too dark, even though the foreground I wanted to light up was only about two to three meters away. There's no exposure indicator so thankfully I could check the K10D's LCD preview and open up the aperture until I got the desired exposure. A bit hit and miss but I was pleased with the results, especially the one below where the heather looks as though it's splashed with sunlight.

Shot late afternoon no filter or flash 1/20sec at f/9	Same exposure but with flash and a grey grad

The indoor test of a couple of silver items on a map was taken at 45mm setting, first with the flash at 0 degree and after viewing the result at the macro setting to prevent the shadow across the bottom.

Shot at 45mm with head at 0	Shot at 45mm with head at -7 tilt position

K10D's built in flash	Sigma EF500 fired

I also did a coverage test indoors by photographing a white wall to see the illumination fall off.

The camera was set on manual and pointed at the white wall. Then I adjusted the focal length and took a photo at various settings to look at evenness of illumination. It was in this test that I spotted what appears to be a flaw in the coupling (Sigma are hopefully confirming what this may have been caused by in the next day or so) As the zoom lens is adjusted the flash head should adjust to suit the lens angle. But the flash always seemed to be setting a smaller angle, this resulted in slightly more uneven illumination towards the corners. In most cases, where the subject is central, you won't notice this, but on evenly toned edges it will become more apparent. I was surprised the 17mm panel coped as well as it did.

Lens set at 16mm with flash panel in use	Lens set at 28mm flash at 35mm
Lens set at 40mm flash at 50mm	Lens set at 45mm flash at 70mm
Lens set at 50mm flash at 50mm	Lens set at 80mm flash at 105mm
Lens set at 40mm f/4 - flash at 50mm	Lens set at 40mm f/22 - flash at 50mm

Sigma EF-500 DG ST verdict
With at least £70 saving on manufacturers own models the Sigma EF-500 DG ST is not to be sniffed at. It's feels a more sturdy build than the budget models from the likes of Jessops and offers dedication that will allow you to feel comfortable shooting in auto on your multi-mode camera. A capable performer although a few niggly things like not having a manual zoom option and independent locks for zoom and swivel tarnish a great performance. I was really pleased with the outside landscapes, once I'd got my head around using a flash that doesn't have aperture settings to choose from. Well worth a look if you're in the market for a versatile flash and can't justify the higher camera brand models.

Plus points:
Almost half the price of manufacturers own versions.
Well built
Uncomplicated and easy to use
Built-in wide angle panel

Minus points:
Battery compartment lid flimsy
Focal lengths didn't match lens
Swivel and bounce locks independent

FEATURES

BUILD QUALITY

PERFORMANCE

OVERALL

The Sigma EF-500 DG ST flashgun is available from the ePHOTOzine shop here