Sigma’s most popular macro lens has been updated, with a new design and the addition of optical stabilisation. Mat Gallagher puts the 105mm f/2.8 lens to the test
The focal length is long enough to provide some distance between you and the subject without the field of view and higher price of a 200mm optic. The Sigma 105mm f/2.8 has long been regarded as one of the best macro lenses for its price. The lens was last updated in 2004, when it was optimised for digital camera sensors.
Apart from some re-chipping to make it compatible with more recent cameras, the lens has remained unchanged. The new Sigma 105mm f/2.8 has been completely overhauled to bring it in line with the Sigma 150mm f/2.8 EX DG OS HSM Macro.
The most notable addition is the optical stabilisation, which has resulted in a much larger, heavier optic and a higher price.
Image: This handheld shot makes use of the Sigma 105mm f/2.8’s optical stabilisation. Nikon D700, 1/25sec at f/6.3, ISO 3200
Features and build
The new Sigma 105mm f/2.8 lens has a completely new lens construction, with 16 elements in 11 groups compared to the 11 elements in 10 groups used for the old version.
These include two SLD (Special Low Dispersion) elements to correct spherical aberration, chromatic aberration and curvature, and super multi-layer coatings on the front and rear elements to reduce flare and ghosting. Unlike the old 105mm version, focusing is internal, using a floating system that moves two lens groups to adjust focus. This avoids the extreme extension of the lens for close focusing that saw the previous lens almost double in size.
The optical stabilisation system appears to be the same as that featured on the recent Sigma 150mm macro lens, among others, and, according to Sigma, it offers a 4-stop benefit in shake reduction. While most precise close-up work should be performed with a steady tripod, when you are shooting handheld any form of stabilisation is very useful.
The stabilisation has two settings, comprising a full dual-axis mode and a single-axis mode for panning. The front filter thread is larger by 4mm, being 62mm in diameter, and it sits much closer to the front element. This should improve optical quality when using a filter. Sigma has done away with the push-pull AF/manual-focus selection of the old model and opted for a simple switch on the new 105mm lens.
On the Nikon-mount version we tested, the focus ring allows manual-focus override when AF is selected on the lens and on the camera.
However, when manual focus is selected on the camera, the AF switch on the lens becomes inactive. The aperture ring that featured on the previous Nikon version has also been omitted. The focus ring sits at the very front of the lens and is fractionally smaller than on the previous model, but it is still broad enough for easy operation.
The focus window contains three readings of distance, in feet, metres and magnification, which is handy for precise reproductions. A focus range limiter switch usefully allows three options for full 31.2cm to infinity, 45cm to infinity and 31.2cm to 45cm to avoid excessive hunting.
The lens comes with a 55mm lens hood, which, when not in use, can be reversed for storage. With the hood reversed it sits snug to the barrel and covers the focus ring and window, but still allows the lens to be comfortably held and used in autofocus.
When used on entry-level cameras the new 105mm lens feels large and bulky in a way the previous model did not. However, with its current specification and price, the lens will probably be used on mid-range or high-end bodies. Here it feels better balanced, and looks very similar to Nikon’s 105mm f/2.8G AF-S VR Micro-Nikkor, which is available at a slightly cheaper street price than the Sigma 105mm.
For testing purposes we used the Sigma 105mm lens on the Nikon D300S, D700 and D3100 DSLRs. Specified as a DG lens, it is designed for both full 35mm frame and APS-C sensor sizes.
The focal length is more suited to a full-frame sensor for standard close-up and portrait use, but as this becomes equivalent to a 157-167mm lens on the smaller APS-C sensor, it is roughly equivalent to the longer 150mm and 200mm macro lenses preferred by wildlife photographers.
As with most macro lenses the effective aperture is given by the camera, and at full 1:1 magnification it loses 2EV of light, giving an effective range of f/5.6 to f/45, compared to the f/2.8 to f/22 at infinity.
Image: The very shallow depth of field of the 105mm lens at 1:1 magnification. Nikon D300S, 5secs at f/22, ISO 200
The inclusion of an HSM (Hyper-Sonic Motor) makes it compatible with non-motor bodies from Nikon and leaves the autofocus near silent, although the stabilisation often lets out a faint ‘squawk’ when first engaged. This sounds a lot like a focus motor of old and could be enough to scare small animals at close range.
While focusing is fairly rapid, even when the change in distance is great, as with many macro lenses, if it misses the focus it takes a few seconds to go through the huge range from 0.312m to infinity, although this can be avoided by using the limiter.
The manual-focus ring is pleasant to operate and, while not that smooth, it still allows the fine and accurate adjustment needed to control close focusing.
Image Quality and Resolution
For the resolution chart images that appear in our camera tests, we use a series of the last-generation Sigma 105mm lenses in various mounts.
This lens was chosen not because of its availability in most mounts but because it was one of the sharpest on the market and would therefore allow us to gain the maximum resolution from the sensor. With the new 105mm model the increase in quality is not drastic, but there are areas that show improvements.
Image: The Sigma 105mm f/2.8 lens is also useful for capturing details, such as this graphic street shot. Nikon D700, 1/1600sec at f/2.8, ISO 200
Resolution at its sweet spot, between f/8 and f/11, shows little gain compared to the original lens, but while the old lens started to show a drop in resolving power when stopped down to f/16, the new model only starts to reduce quality beyond f/22.
This is an extremely strong performance and one that will allow the maximum quality to be realised from the highest resolution sensors. Vignetting can be seen when the lens is used at the maximum aperture on a full-frame camera. However, the appearance is slight and can easily be removed in raw editing, and it disappears when the lens is stopped down to f/5.6. When used on an APS-C body there is no sign of vignetting.
Neither barrel nor pincushion distortion is visible in our test images, and at this focal length you would not expect to find them. The lens produces a crisp contrast, which emphasises the sharp areas of the image against the out-of-focus areas. The increase from 8 to 9 diaphragm blades was designed to help produce a smoother out-of-focus area, or bokeh, but at the smallest aperture the blades don’t quite create a perfect circle and the jagged edges can be seen in the out-of-focus highlights it creates.
We tested the Sigma 105mm f/2.8 EX DG OS HSM Macro on the Nikon D700 camera against the older Sigma 105mm f/2.8 EX DG lens. As the D700 is a 12.1-million-pixel camera, the values should be used for comparison and not as a value for the total performance of the lens.
While the second-generation Sigma 105mm was very much a budget lens, this new third-generation model demands a current street price higher than its Nikon equivalent and only £20 short of the Canon L-series 100mm macro.
For the extra money the new version offers some impressive refinements, such as stabilisation and internal focusing, but it is image quality that matters most here. The optical performance is a marked improvement and although detail is only a small part of this, the original standard was already very high.
Image: A splash frozen with flash, showing the impressive detail that can be captured with the Sigma 105mm lens. Nikon D700, 1/125sec at f/20, ISO 100
The problem this lens faces is that, instead of being an impressive budget lens, it is priced as a premium optic over the camera brands’ own versions. This is not the first time Sigma has taken this position – the Sigma 50mm f/1.4 was also a higher price than its Canon and Nikon competitors – but it means that the lens has to prove itself far more to win over users.
The 105MM standard macro focal length is more suited to full-frame sensors, so producing a premium-positioned lens makes sense. For APS-C cameras, Sigma’s 70mm macro gives an effective 105mm or 112mm for Canon users and is therefore a better focal length.
The Sigma 105mm f/2.8 EX DG OS HSM Macro is an impressive lens that feels robust and handles well. The internal focusing is a welcome addition and, although the stabilisation has added weight and bulk to the lens, it is useful for handheld work at less than 1:1 magnification.
The quality of the optics has been improved to provide greater resolution and less vignetting than the previous model, bringing it to levels expected in this price range.
The problem is that Sigma may have created a space in the market for a budget macro lens.
Those searching for an affordable alternative around this focal length are now more likely to opt for the Tamron 90mm or Tokina 100mm than pay almost double for the extra features of Sigma’s new model.