Sigma made their mark by being proactive when autofocus SLR cameras appeared back in 1985 and now they are applying the same approach to digital. With the new breed of digital SLRs comes a new demand for wider lenses. Most SLRs use a smaller CCD than film so the actual image produced by the lens is cropped and effectively magnified - usually by about 1.5x. As more press and enthusiasts take to digital they often can't afford the super wide-angle that they are used to. Enter Sigma.
The 17-35mm EX D is one of a new range of D series lenses that offer digital photographers an affordable solution. With the magnification increase you're still have a useful 25-50mm focal length range.
The lens is an f/2.8-f/4 model that operates at the fast aperture of f/2.8 at the 17mm setting and slows down to f/4 at the 35mm setting. It's chunky but, thanks to some nifty design tricks is relatively lightweight
I tried the Nikon fitting that suits the Fuji S1 and Nikon D SLRs on the Fuji S1. It can also, of course, provide a superb 17-35mm range on a 35mm camera, and here an old Nikon F3 became host.
The lens is stylish - Sigma's familiar Zen style coating on the barrel, with a shiny gold ring towards the front. Barrel markings indicate the focal length, focusing range and a basic depth-of field scale. On the Nikon there's also an aperture ring. The filter
thread is a huge 82mm, which will become costly if you want to add a polarising filter
or a protective UV.
Two grips are provided - one for the zoom, which is beautifully smooth and the other for the manual focusing, which is released by a small switch on the body or side of the lens, again depending on the model. The manual ring is loose to turn, but it has to be to ensure there's no strain on the AF motor.
The mount is metal and fits tightly to the body and the image delivered through the viewfinder is bright into the corners. It's also responsive on the camera when focusing.
Now to performance. On a digital camera you don't get to see the true ultra-wide benefit of this lens as the effective 25mm focal length is just on the edge of those lenses that create dramatic sweeping imagery, but it's better than not having wide at all! The results are sharp, and here's a lens that can be trusted. Centre detail is crystal clear with almost no fall off at the edges on the frame. Illumination across the frame is also really consistent. Colours are captured faithfully and the focal lengths are accurate, measuring up to the figures quoted by the manufacturer.