Sigma 30mm f/1.4 DC HSM Art lens

      Photo Review 9
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      In summary

      Weighing only 435 grams, the Sigma 30mm f/1.4 DC Art lens  is light enough to be used while travelling and its 45mm equivalent focal length is close to the classical 50mm focal length that was popular with 35mm film photographers.

      The fast maximum aperture makes it usable for portraiture as well as wedding and event photography.  Low levels of distortion enable it to be used for architectural applications.

      There are a few downsides to consider (see full review), however its  robust construction, attractive bokeh and quiet auto-focusing make it worthy of consideration by owners of other cameras with APS-C sized sensors.

      It also comes at an affordable price.

       

      Full review

      A current member of Sigma’s Art line of lenses, the 30mm f/1.4 DC HSM lens updates a popular model from 2005 with a new optical configuration, a new hypersonic motor (HSM) autofocusing drive and rear focusing system. Full-time manual focus override is supported. The lens barrel remains the same length during focusing and the front element doesn’t rotate, allowing angle-critical filters to be used without requiring re-adjustment.

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       Side view of the Sigma 30mm f/1.4 DC HSM Art lens with the lens hood and end cap fitted. (Source: Sigma.)

      The optical design consists of eight elements in nine   groups and includes one double-aspherical element to control spherical distortion, astigmatism and coma. Nine rounded diaphragm blades close to a circular aperture, producing attractive bokeh. Optimised power distribution helps to minimise field curvature and maintain image quality across the image frame. Sigma’s Super Multi-Layer Coating reduces flare and ghosting.

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      This diagram shows the position of the aspherical element in the optical design. (Source: Sigma.)  

      The angle of view of this lens on the sd Quattro camera we used for our tests is equivalent to 45mm on a 35mm camera, which is similar to that of human vision. Its minimum focusing distance is 30 cm, which gives a maximum magnification ratio is 1:6.8. No stabilisation is provided.

      A rear-focus system prevents focus-dependent variation in aberration, while a new optimised auto focus (AF) algorithm ensures smooth and accurate focusing. The lens is supplied with a re-designed lens cap, end cap and cylindrical lens hood. It is offered with mounts for Canon, Nikon, Pentax and Sony as well as the Sigma mount version we tested.

      The updated 30mm f/1.4 lens is compatible with  Sigma’s new USB Dock, which allows firmware updates and focusing adjustments to be applied via a personal computer.

      Who’s it For?
       Weighing only 435 grams, this lens is light enough to be used while travelling and its 45mm equivalent focal length is close to the classical 50mm focal length that was popular with 35mm film photographers. The fast maximum aperture makes it usable for portraiture as well as wedding and event photography. Low levels of distortion enable it to be used for architectural applications.  But the lack of stabilisation could be off-putting to some potential purchasers.

      Build and Ergonomics
      Much of this lens is made from metal, which equates to superior build quality. The outer barrel has a glossy finish, which feels cool to the touch. The lens mount is made of brass with a chromed finish. It fitted very solidly onto the camera body.

      Some internal and external components have been made from Thermally Stable Composite (TSC), which is a good match for the metal parts and contributes to the high-precision construction of the lens. TSC also makes it possible to use slimmer designs for the movable adjustment rings.

      The HSM (hypersonic motor) AF delivers fast and extremely quiet focusing performance, making this lens suitable for movie shooting (which isn’t supported in the review camera). The rear focusing system prevents focus-dependent variations in aberration and contributes to the overall performance.
       There’s only one control ring; the focusing ring, which is 20 mm wide and located just behind the bayonet mount for the lens hood. It has a 12 mm wide finely-ridged rubber-like grip band and turns freely through 90 degrees.

      This ring is connected to a distance scale, which is inset into the lens barrel just behind the focusing ring. It has a transparent plastic cover and displays distances from 30 cm to infinity. Depth of field indicators are not included.

      Level with the distance scale on the left hand side of the lens barrel is a slider switch with AF and MF settings for swapping between auto and manual focusing. There are no other external controls. The lens barrel is straight and smooth for about 14 mm before stepping inwards to its mounting plate.

      Performance
       Without being able to test this lens on a camera with a Bayer-filtered sensor, we can only report on its performance with the Foveon chip, which is renowned for its high resolution. As noted in our review of the Sigma sd Quattro camera (INSERT LINK), the Foveon sensor and the 30mm f/1.4 DC HSM Art lens are a winning combination that exceeded resolution expectations in our Imatest tests.

      Resolution remained high at all aperture settings, although some edge and corner softening was evident at the widest lens apertures. However, when stopped down to f/2.5, both centre and edge resolution were excellent. Resolution stays relatively high throughout the rest of the aperture range with only slight diffraction-related softening at f/11 and f/16, as shown in the graph of our Imatest results below.

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       Lateral chromatic aberration wasn’t so good, although it remained mostly within the ‘low’ band, as shown in the graph of our Imatest results below. The red line separates negligible and low CA, while the green line marks the edge of the moderate CA band.

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       Interestingly, only traces of coloured fringing could be seen in most test shots so we’re not sure how the Imatest tests came up with these results. Some fringing could be seen in out-of-focus areas in close-ups, however.   Other reviewers have reported visible coloured fringing when this lens was tested on cameras that had normal CMOS sensors with Bayer filtration.

      Flare artefacts appeared in shots taken with a bright light source just outside the field of view, even when the lens hood was fitted. However, normal backlighting was usually handled quite well.

      Slight barrel distortion could be seen in test shots taken with the review lens but it would be very easy to correct in an image editor on by a camera with integrated lens corrections.  We suspect it would only be relevant to photographers taking architectural or product shots or landscape photographers taking shots that included horizons. Vignetting was obvious at f/1.4 but stopping down to f/2.8 eliminated it.

      Autofocusing speed depends on the camera you’re using. On the sd Quattro the HSM motor was very quiet but it could take a second or more for the camera to find focus in tricky situations. We suspect that on a more responsive camera this lens would probably focus quickly and accurately.

      With a minimum focusing distance of 30 cm and a maximum magnification ratio of just 1:6.8,  this lens is not well suited to close-up work. But it can be used for close-ups of suitably-sized subjects and produces smooth and attractive bokeh at wider aperture settings.

      Conclusion

      The Sigma 30mm f/1.4 DC Art lens covers an uncommon angle of view equivalent to 45mm on a 35mm camera. It’s not quite a true ‘standard’ lens but not wide-angle, either.

      Both physically and in imaging performance we found it to be a good partner for the sd Quattro camera we used for our tests, although it was hampered by the camera’s sluggish responsiveness. Its robust construction, attractive bokeh and quiet auto-focusing make it worthy of consideration by owners of other cameras with APS-C sized sensors. It also comes at an affordable price.

      There are a few downsides to consider, however.  Chromatic aberration is an issue unless the camera you use provides in-camera corrections (although if it does, they may not cover third-party lenses). Vignetting and barrel distortion should also be taken into account, although both can be easily corrected when converting raw files into editable formats.

      Sigma’s online shop has this lens listed at a discounted price of US$379 (just over AU$496), down from the original $499 MSRP, although the local distributor ‘s website doesn’t reflect this discount.   The local RRP for it is AU$699 but if you shop around you’ll pay much less.

      Expect to save at least AU$150 by buying from a local re-seller. Even though some re-sellers in the USA are offering it for US$339 (roughly AU$449), when you add in the shipping and insurance costs, it’s not worth the effort of shopping off-shore.  

       

      SPECS

       Picture angle: 50.7 degrees
       Minimum aperture: f/16
       Lens construction: 9 elements in 8 groups (including 1 aspherical lens element)
       Lens mounts: Sigma, Sony, Canon, Nikon and Pentax (APS-C sensors only)
       Diaphragm Blades: 9 (circular aperture)
       Focus drive: HSM (hypersonic motor)  
       Stabilisation: No
       Minimum focus: 30 cm
       Maximum magnification: 1:6.8
       Filter size:   62 mm
       Dimensions (Diameter x L):74.2   x 63.3 mm
       Weight:  435 grams
       Standard Accessories: Lens front and end caps, lens hood (LH730-03)

       Distributor: C.R. Kennedy & Company; (03) 9823 1555; www.crkennedy.com.au  

       

      TESTS

       Based on JPEG files captured with the Sigma sd Quattro camera.

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      SAMPLES  

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      Vignetting at f/1.4.

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      Rectilinear distortion.
       

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       Close-up at ISO 200, 1/1000 second at f/1.4.

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      Crop from the above image at 100% magnification showing the resolution of fine details.
       

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       Flare from bright light source outside the frame; ISO 100, 1/320 second at f/11.

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      Strong contre-jour lighting; ISO 100, 1/640 second at f/8.
       

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       Crop from the above image at 100% magnification showing negligible coloured fringing.
       

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      ISO 200, 1/4000 second at f/1.4.
       
      Additional image samples can be found with our review of the Sigma sd Quattro camera.
       
       

      Rating

      RRP: AU$699; US$499

      • Build: 9.0
      • Handling: 8.5
      • Image quality: 8.8
      • Versatility: 8.3

       

      Buy