This Sigma 12-24mm has been a popular choice for photographers, with nothing on the market that wide without producing a fisheye effect. The new Sigma 8-16mm provides APS-C size camera users with exactly the same angle-of-view as the 12-24mm does on full frame, opening up new possibilities to a wider photographic market.
The Sigma 12-24mm F4.5-5.6 wide angle zoom has remained unique for users of full frame film or digital. No camera manufacture has yet even tried to make a similar lens. If you think the Nikon 14-24mm might qualify, think again – there’s a really huge difference between 12mm and 14mm.
I have used the 12-24mm from 2003 onwards when it was launched, in four different mounts – Canon (for a full-frame Kodak with Canon mount), Nikon (similar), and Sigma’s own S-mount with an SA-7 film body for maximum coverage, an SD-9 for the first digital tests, and in Sony Alpha for my full frame 900.
With no facility to use filters on full frame due to the curved front element and built in lens hood wings, the 12-24mm does allow 82mm filters to be fitted for smaller digital formats via its two-part lens cap, the tube of which has a filter thread. There have been more effective solutions for the APS-C format including Sigma’s own 10-20mm which arrived a little later, taking 77mm filters.
But there has been no 12-24mm equivalent for APS-C. The 10-20mm was actually an APS-C version of the Sigma 15-30mm f/3.5-4.5 full framer, but with a reduced maximum aperture allowing a design which has a normal filter thread.
Now we have the 12-24mm scaled down – from the same designers responsible for the 12-24mm. The 8-16mm f/4.5-5.6 does exactly the same for 1.5X (DX) format users as the 12-24mm does for full frame.
I’ve been using the 12-24mm on Sony Alpha 900 for two years now. It has no chromatic aberration at 12mm, but my lens suffers from softness to one side and is better at 12mm than 24mm. This is not unusual, and can be down to the camera’s sensor alignment, not the lens. Parallelism is an issue at such short focal lengths, and I normally stop down to f/11 to get critically sharp results for professional work.
The 8-16mm arrived in Nikon fit and was tested on my Nikon D5000, which at 12 megapixels was the highest resolution available for Nikon DX format until a couple of months later when the D7000 was revealed with 16 megapixels. But I have not been able to try it yet on that body! It is much neater and slimmer than the 12-24mm full framer, and has the same domed front element and built-in petal hood. The lens cap’s retaining tube accepts 72mm filters but you would have to crop the image for this to be useful.
The 12-24mm has not been updated to HSM in all fittings, and Sigma UK’s Paul Reynolds agrees that HSM (sonic motor) focusing is not strictly needed for such wide lenses – it’s needed only because some cameras lack in-body focus motors. Thus the Nikon 8-16mm lens is HSM, and must be, to work with the popular range of DX format Nikons such as the D3100.
It displays the same pretty much perfect geometry at 8mm as the 12-24mm does at 12mm. The lack of compound distortion in this lens always amazes me. The 12-24mm is bought for its 12mm performance and little else. The 8-16mm is a close match at 8mm.
However, it does not look as sharp – perhaps because I am used to full frame – and there is some visible chromatic aberration. As a quick comparison confirmed in Photoshop CS5 using Adobe Camera Raw 6.2 which has correction profiles for Sigma lenses, the 8-16mm does have a little more distortion too. When auto correction is applied, some wide angle effect is lost due to the way the distortion is optimised, and the trace of CA is removed.
Vignetting is no worse than many lenses twice the focal length. To cover 114.5° and not show an extreme darkening to the corners is some feat of design. Sigma has used four LD glass elements, one hybrid (glass-polymer) aspheric and two moulded aspherics in this design. That’s more exotic elements than you’ll find in any similar lens, I think; corrections on a postcard please…
Things remain good as the lens is zoomed in to 16mm. While the 12-24mm is known to lose its bite at the long end, the 8-16mm is very evenly balanced and the quality at all focal lengths from 8 to 16mm remains good. There is much less distortion at 16mm, and it is a more conventional slight barrel which corrects without losing visual angular coverage.
I am confused, a bit, by Sigma’s own web pages. The 12-24mm is stated to give 122° coverage, but the 8-16mm is quoted as 114.5°. I guess this is because APS-C is not always a true 1.5X factor, with sensors closer to 23mm than 24mm long dimension – and Canon sensors even smaller, meaning you can never get the full benefit of wide angles. But Sigma’s own SD-1 when it arrives has a true 24 x 16mm 1.5X sensor so it will get the entire 122° the 8-16mm should be capable of.
As for choice, there is not even one single prime straight line wide-angle fixed focal length of 8mm on offer, from any maker, for APS-C/DX format. Just as with the 12-24mm where no 12mm SLR lens has ever been made, Sigma once again offers the only option.
The 12-24mm has had a long career, revitalised by the arrival of full frame digital. Now this DX-format, two-thirds scaled down 8-16mm joins it.
– David Kilpatrick