Many thanks to Gene (FM Forum: gasrocks) for providing the lens for testing.
Sigma APO Macro 180mm f/3.5 EX DG HSM is the longest of Sigma's five dedicated macro lenses currently available on the market. The lens is currently being manufactured for Canon, Nikon, Sigma, Pentax and Sony mounts. Sigma first released the lens in May of 2005 as a quality alternative to the often overpriced native macro lenses like Canon's EF 180mm f/3.5L Macro USM. The lens is priced at ~US$800 (as of August 2008), making it a whopping US$500 cheaper then Canon's 180mm macro lens and Nikon's 200mm macro lens. Not too shabby.
The optical construction of the lens consists of 13 elements in 10 groups, including 2 SLD (Super Low Dispersion) glass elements designed to reduce various forms of aberration. The lens implements a floating inner focusing optical formula, which is said to improve image quality at close focusing distances. Additionally, inner focusing means that the inner cams of the lens do not extend during focusing, leaving the overall length constant at all times. The build quality of the lens is superb - the barrel is made of lightweight metal and has a crinkle-style finish to it. There is no wobbling inside or out and the lens looks and feels quite sturdy. The broad focusing ring is fully rubberized and is easy to rotate. The lens is not the most or light 180mm prime out there - at 965g (34oz) and 80 x 182mm (3.1 x 7.2in) it resembles its Canon rival.
Sigma APO Macro 180mm f/3.5 EX DG HSM incorporates a near silent hyper sonic focusing motor. The lens support both automatic as well as manual focusing, which can be controlled with an AF/MF switch on the side of the barrel. However, the lens can be fine-focused manually while still in the AF mode - simply auto-focus the lens, then adjust the focus manually to achieve desired level. To improve the speed of auto-focusing, Sigma incorporated a focusing limiter switch with three modes - mode 1 from the closest minimal distance of 46cm (18.1in) to the infinity, mode 2 for the closeup photography from 46cm to 81cm and mode 3 for telephoto photography from 81cm to the infinity. This is a step above the typical focusing limiter capabilities found in many of Canon's lenses.
Like most modern lenses, Sigma APO Macro 180mm f/3.5 EX DG HSM incorporates a fully electronic aperture control. There is no dedicated aperture ring and all settings have to be controlled directly from the camera. The minimum focusing is f/32. The front element of the lens does not rotate, allowing the use of circular polarizers. The lens accepts 72mm screw-in type filters.
The factory box includes Sigma APO Macro 180mm f/3.5 EX DG HSM lens, front and rear caps, tripod mount, LH780-02 metal lens hood, semi-hard lens case, manual and registration card. The lens is compatible with Sigma's 1.4x and 2x APO Tele Converters. Designed for full frame cameras, the lens will have a field of view equivalent to that of a 288mm prime if used on an APS-C body with 1.6x crop factor. Within the scope of this review, the lens was tested on Canon's FF 5D and APS-C type 400D.
|Lens Composition||13 elements in 10 groups|
|Angular Field||~13 degrees|
|Focusing Action||AF/MF, HSM-type|
|f-stop Scale||f/3.5-f/32, camera-controlled|
|Lens Hood||LH780-02 (included)
|Lens Case||Semi-hard case (included)|
Field TestsSigma APO Macro 180mm f/3.5 EX DG HSM is your typical telephoto lens, meaning that it behaves and handles like one. With one obvious exception - it's also a macro lens. More about the macro a bit later, but the first thing I wanted to mention is the three mode auto focusing limiter, which turned out to be a major boon for macro work. Most telephoto lenses include two mode limiters that help improve the performance in the telephoto range (the typical configuration is to have a closeup to infinity and closeup+delta to infinity modes). If you're working at macro distances, then the telephoto limiter is of no use, so you end up with the lens that focuses along the entire focusing distance. Depending on the quality of the auto-focus system incorporated into your camera and/or lens, this might result in a pretty long focusing time. Here, the Sigma's macro limiter comes especially handy since it instructs the lens to focus only within the narrow range suitable for macro work. The outcome? Faster focusing at macro distances.
The lens performed quite well in the field. Produced images carried excellent overall resolution. Center, as well as border quality were top notch on both full frame as well as APS-C cameras and there did not seem to be any visible difference in image quality across the frame and across of all aperture settings. At least if there were any differences, they were not easily noticeable through image 'eyeballing'. Although, at macro distances and with wide open aperture, the lens produced images with pretty shallow depth of field, so visually comparing quality around borders obviously has its limits.
When shot with wide open aperture, Sigma APO Macro 180mm f/3.5 EX DG HSM produced well rounded, uniformly lit out-of-focus highlights with neutrally lit edges (although you could spot a few harsher edge highlighting in the image above). Contrast transitions in near and far OOF areas were pretty smooth and there was no sign of double-edging around OOF objects, which should help to the general feel of bokeh.
One of the more interesting aspects of the lens is obviously its 1:1 macro capabilities. As mentioned earlier, Sigma APO Macro 180mm f/3.5 EX DG HSM is one of the longer telephoto macro lenses currently available on the market. This can be useful in situation where getting close to a photo target is impossible or undesirable, for example when shooting insects prone to scattering in all directions with the slightest sense of movement. However, keep in mind that if you are using the lens on an APS-C camera, your working distance will actually increase by 50 to 60% (depending on the crop factor of the sensor in your camera). A 290mm macro lens (that's what your 180mm Sigma will turn into on a Canon Digital Rebel XTi)? Personally, I never needed one, but then again your needs might be different.
The lens produced mild to moderate amount of vignetting on a full frame camera at f/3.5. This is a little bit disappointing, considering that we're dealing with a telephoto lens of moderate speed. Still, vignetting persists at f/4 but pretty much goes away around f/5.6. And on an APS-C camera, the lens showed basically no vignetting throughout the tested aperture range.
Sigma APO Macro 180mm f/3.5 EX DG HSM showed pretty good handling of lens flare. The images below demonstrate the impact of a string direct light source positioned near the picture frame. The sun in these images was hitting the lens at ~50 degress from the right top side. As you can see, the flare did impact the overall contrast of the images, with colors looking more smudged then one would experience in normal normal conditions. Furthermore, the lens also showed minor level of ghosting at smaller apertures - notice the bleak area in the left bottom corner of the image on the right hand side. Still, the artifact is not the worst one could experience in such harsh lightning conditions.
Speaking of the colors and contrast. The lens actually showed pretty good color handling outside of the extreme lightning situations described above - color reproduction was quite accurate, with images showcasing good amount of contrast and separation across the aperture range. The lens showed no visible distortion, which comes as no surprise for a telephoto prime. The lens also showed good handling of color fringing, with no major signs of longitudinal or lateral chromatic aberration.
Please note that MTF50 results for APS-C and Full-Frame cameras as well as cameras from different manufacturers are not cross-comparable despite the same normalized [0:1] range used to report results for all types of cameras.
Canon APS-C: Sigma APO Macro 180mm f/3.5 EX DG HSM showed very solid image performance on a Canon 400D. Overall performance was somewhat stronger at wider apertures, slightly dropping towards f/11. But even at f/11 the quality remained quite good. Moreover, the lens showcased very balanced performance across the entire frame, with no major changes in quality from the center to the borders. The lens is capable of delivering excellent 16in prints across the entire tested aperture range, and decent 24in prints at its widest apertures. Conclusion? Very solid results among both macro as well as telephoto lenses.
The lens showed good handling of chromatic aberration on an APS-C camera. Center CA was very low throughout the tested aperture range, never exceeding ~0.3px. Border CA, while somewhat higher, especially at f/3.5 where it approached ~0.7px, was still manageable. From ~0.7px at f/3.6 CA continued to drop down to ~0.5px by f/11.
Here are 100% crops, taken with an APS-C type Canon 40D, comparing image borders at f/3.5 and f/8.
Canon FF: The lens continued to demonstrate very solid results even on a full frame camera, with overall performance mimicking that experienced with an APS-C body. Image quality remained somewhat better at wider apertures, degrading in quality a little bit towards f/11. 'Degrading' is a relative term here obviously, since even at f/11 image quality remained quite respectable and the drop in performance was quite minimal -about 12% across the frame. Both center as well as border image quality were very well balanced across the entire aperture range, which is a major positive characteristic in any lens. Conclusion? Very good performance across the frame, with basically no compromises. What else might one need?
Sigma APO Macro 180mm f/3.5 EX DG HSM showed negligible amount of barrel distortion, and at ~0.48%, distortion should not bother you in most type of photography.
Chromatic aberration on a full frame camera was also quite low, never exceeding ~0.2px in the center and ~0.7px around borders across the entire tested aperture range.
Here are 100% crops, taken with a full frame type Canon 5D, comparing image borders at f/3.5 and f/8
Sigma alone currently manufactures five dedicated macro lenses, so obviously the question of alternative macro lenses really comes down to first selecting the focal length suitable for your needs and then narrowing down your selection. Assuming you are interested in telephoto macro lenses, then the two other Sigma macro lenses to consider are Sigma APO Macro 150mm f/2.8 EX DG and Sigma Macro 105mm f/2.8 EX DG. Both are available in a number of camera mounts, offer excellent build quality and good handling. If you're shooting with Canon cameras, then you might want to consider Canon's excellent EF 100mm f/2.8 Macro USM, which delivers excellent image performance at a very reasonable price. And if you are using and APS-C camera, then you might also look into Tokina's AT-X AF PROD D 100mm f/2.8 Macro. Tamron's excellent SP AF 90mm f/2.8 Di Macro as well as SP AF 180mm f/3.5 Di LD IF Macro are two other interesting choices for macro photographers. One might also consider Canon's EF 180mm f/3.5L Macro USM, which matches the Sigma's length in focal length. However, Canon's lens does not really offer any improved image characteristics or build quality and sells for ~US$500 more then its SIgma competitor. A couple of other potential macro alternatives might be suitable for those of you who can tolerate manual focusing and/or are willing to adopt an alternative mount lens to your favorite SLR body. The choice is quite wide here. Start with Voigtlander APO Lanthar 125mm f/2.5 SL, which unfortunately has been discontinued for some time now. Among the alternative mount lenses consider Leica's APO Macro Elmarit-R 100mm f/2.8, Carl Zeiss Makro-Planar T* 100mm f/2 ZF (as well as its older, Contax branded version Carl Zeiss Makro Planar T* 100mm f/2.8). And don't forget to check out Nikon's AF Micro Nikkor 200mm f/4D ED IF and Micro Nikkor 105mm f/2.8 Ai-S. Finally, you might also check out the Macro Challenge, which compares a number of macro lenses side by side.
Sigma APO Macro 180mm f/3.5 EX DG HSM is a very strong contender among telephoto macro lenses. The lens combines very strong image performance on both full frame and APS-C cameras, excellent build quality, low level of distortion and good color handling, all that at very aggressive price. There does not seem to be any glaring weaknesses with the lens and that by itself is a major achievement. So if you are in the market for a telephoto macro, then Sigma's 180mm macro lens should most certainly remain at the top of your list.