Handling and features
It is one of the most popular macro lenses around, and ePHOTOzine's Gary Wolstenhome checks it out
Sigma's 105mm macro optic costs around £380, which is the same price as their more recently released 70mm F/2.8. The 105mm gives a little comfortable working distance, which should make it easier to light your subjects at high magnification, and you are less likely to scare off the subject. It is also more flattering for portraits.
The 90-105mm macro market is incredibly crowded, with each manufacturer offering at least one lens in this range. Tamron's well regarded 90mm F/2.8, also offers 1:1 magnification and is a bit cheaper at around £335. Tokina's 100mm F/2.8 lens is also a little cheaper at around £340.
Canon currently offer two lenses in this range. Both have internal focus designs and Ultrasonic Motor (USM) focusing. The older and cheaper of the two costs around £435 and the newly released L series 100mm costs around £780 but the latter lens also has an Image Stabiliser.
Nikon's 105mm Micro lens also has an internal focus design, Silent Wave focusing motor and Vibration Reduction, but costs around £605.
Pentax currently offer two macro optics. The newer and more expensive of the two costs around £500, is weather sealed and has a special Water Repellent coating on the front element, to reduce marks. Tho older, more basic version is very similarly specified to this Sigma lens and costs around £495. Sony also offer a 100mm macro optic which costs around £515.
Sigma 105mm F/2.8 EX DG Macro: Handling and features
Sigma's powder coated finish has been applied to much of the exterior plastic, which not only looks quite smart, but adds to the quality feel. As with many lenses from Sigma's EX series, the front of the focusing ring is nicely finished off with a gold band and the knurled rubber focusing ring takes up much of the lens barrel. The lens feels solidly put together, without being too heavy.
Sliding the focus ring back and forth switches between manual and autofocusing modes. There is no need to move any other switches or levers on the camera or lens. This is great for when you need to change modes quickly.
At its closest focus, this optic is almost double the length it is when focused at infinity. The front element is deeply recessed within the body of the lens, reducing the need to use the supplied hood, which can help with getting light on your subject when at 1:1 magnification.
Autofocus is slow, and quite noisy when compared to similar optics. A focus limiter switch does help to keep hunting to a minimum, but the AF action jus doesn't feel as refined as many similar optics. Manual focus is a different story altogether. The focus ring is nicely damped, providing just enough resistance for making fine adjustments quickly and easily.
Sigma 105mm F/2.8 EX DG Macro: Performance
For this review, the lens was tested on a 12Mp Nikon D700 using Imatest.
On Nikon cameras, the effective aperture of the lens is displayed as the lens is focused closer. On most other macro lenses, the aperture value is unaffected until you start to focus in closer then a metre or two. Strangely, this Sigma is only f/2.8 when focused at or beyond infinity. That is why the resolution reading display starts at f/3, rather than at f/2.8.
At maximum aperture, the lens produce acceptable centre resolution and fair sharpness towards the edge of the frame. This certainly isn't poor performance, but I expected better of a lens with such a good reputation amongst photographers. Stopping the lens down improves matters, with the lens performing at its best when set at f/8. Here it produces images with very good sharpness in the centre, and the resolution remains good towards the edges of the frame. Diffraction begins to rob the lens of sharpness at smaller apertures, but the resolution is still good at f/16 and acceptable by f/22.
Resolution at 105mm
Chromatic aberrations are kept to low enough levels for you not to have to worry about them. Imatest barely registered a quarter of a pixel-width of colour fringing, even in the far edges of the frame.
Chromatic Aberrations at 105mm
For a wide aperture lens, light falloff towards the corners is well controlled, with the corners only being 1.1stops darker than the image centre at maximum aperture. Stopping down to f/5.6 provides uniform illumination across the frame.
As you might expect for a fixed-focal lens, distortion is well controlled. Imatest only registered 0.391% pincushion distortion, which should pose few problems, even for critical applications.
This lens keeps flare and ghosting to a minimum. Strong point sources of light in the frame will cause a little flare under extreme circumstances, but even then contrast is fairly well preserved. Light sources outside the frame pose few problems, thinks in part to the deeply recessed front element. There really is no need for a hood with this lens. Sigma provide one anyway, just in case.
Sigma 105mm F/2.8 EX DG Macro: Verdict
Although this is a good lens, capable of producing images with very good resolution, I am left a little unimpressed by the resolution, especially at maximum aperture. Maybe I expected too much given the lens' reputation? Still I feel other similarly priced lenses offer more in this area.
Otherwise, the build quality is very good and the handling superb. If only the AF action could be a little more refined. Saying that, taking the price into account, if you require a 105mm macro it still represents decent value and many will still be more than happy with the performance of this optic.
Sigma 105mm F/2.8 EX DG Macro: Pros
VALUE FOR MONEY
Good build quality
Easy to switch between manual and auto focus
Smooth manual focus action
Recessed front element reduces need to use supplied hood
Sigma 105mm f/2.8 EX DG Macro: Cons
Lacklustre performance at maximum aperture
Slow, noisy AF
Sigma 105mm f/2.8 EX DG Macro: Lens specification
The Sigma 105mm F/2.8 EX DG Macro costs £373.99 and is available from Warehouse Express here:
Sigma 105mm f/2.8 EX DG Macro - Canon fit
Sigma 105mm f/2.8 EX DG Macro
- Nikon fit
Sigma 105mm f/2.8 EX DG Macro - Sigma Fit
Sigma 105mm f/2.8 EX DG Macro - Sony/Minolta