A Sigma 10-20 f4-5.6 on a Canon 60D (and a new post-processing program!)

I’ve been doing some test shoots recently for a long-term video project, and have finally hit the need for something wider than the 15mm (24mm equivalent) wide setting on my 15-85mm Canon lens. Not wishing to shell out too much as I seldom use this focal length for stills, I decided the Sigma 10-20mm lens (16-32mm equivalent) would be worth a try as it’s 2/3 the cost of the Canon APS-C equivalent, and according to the online reviews, not too bad at all. If you’re considering one – or just interested – read on!

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On the 60D – quite nicely balanced and pretty light.

The lens is constructed of good quality plastics with a zoom ring (back of the lens) and manual focus ring (front of the lens) along with a snazzy gold band near the filter. There’s a focus distance window which looks nice but isn’t very useful due to the deep depth of field on all wide-angle lenses (the marking after infinity is 3m!). The only other controls are the AF/MF switch and depth of field button. The filter thread is 77mm – filters will be expensive but that wide diameter is inevitable in a lens of this extreme focal length and format. Minimum focus is around 24cm but the wide-angle distortion at that distance is ferocious so not an ideal macro lens…

Everything seems to work smoothly with no unevenness in the zoom and focus controls. Minimum aperture is f22 at the 10mm end or f32 at the 20mm end, though at these small apertures dust spots on a sensor will show easily and diffraction will start to make things very soft. A neutral density filter would be a better solution if you want to use a slow shutter speed.

So no bells and whistles but everything that’s needed. There’s no image stabilisation but at these focal lengths slower shutter speeds are more useable so it’s not that useful anyway.

On to the coverage – all taken from the same spot.

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The view at 10mm and 16mm equivalent in 35mm camera terms. 102 degrees from left to right so pretty wide and what you would use this lens for for 90 percent of the time.

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At 14mm ish and around a 24mm in 35mm camera terms.

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At 20 mm – 32mm equivalent in 35mm camera terms.

    Stills results are, as you’d expect for a lens of these extreme focal lengths and price, best described as ‘variable’. At maximum apertures and all focal lengths the frame edges are noticeably soft but the centre is sharp enough. However stop it down to f8 to f11 and things improve dramatically to a point where they are very impressive. Past f11 the performance drops off quickly as diffraction starts to soften the image. Distortion and vignetting at the 10mm end are noticeable, again as expected but chromatic aberration is minimal.

  The HD video results are fine – the final images are only 2Mp after all. However, finding this lens to be pretty good at controlled apertures for stills, I inevitably wanted to see how the results could be improved in post processing and hit a snag….

  If you’re a RAW shooter who uses Canon’s supplied DPP software (as I am) you’ll now face a problem correcting distortion, chromatic aberration and vignetting. DPP only supports Canon lenses – they aren’t interested in supporting third-party lens sales! However, DXO provide a solution in the form of Optics Pro 8 which is a sort of DPP for many camera bodies and lens combinations, and seems pretty good at correcting not only this combination but hundreds of others.

  So for the test shot – processed in DXO Optics and taken at the 10mm end at f8 at 1/250th of a second, ISO 100.

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At 10mm and the distortion to the near right garages is obvious but inevitable. Keeping the lens perfectly horizontal would have helped.

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The uncorrected result (chromatic aberration correction turned off) from left centre of the frame. There is some red CA between the white window frame and dark window glass. For a budget lens at this extreme focal length this is superb – but still needs correcting!

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The corrected image – CA has gone and the whole image is nicely sharpened – magic!

So a very acceptable result at a budget price – even with the additional cost of the DXO software it’s still cheaper than the Canon EF-S lens (which I’m sure is very good). In addition Optics Pro corrects the results on shots taken with all my old cameras including the Canon G9 and Olympus EPL3 as well as the ‘in use’ RX100 and 60D with Canon lenses. MF lenses aren’t covered unfortunately (maybe an unrealistic expectation), but a version of DXO filmpack is included in the package so it manages to replace three post-processing programs. I’m impressed!

Hope you find this useful and thanks for looking.

p.s. I’m not connected with Canon, DXO or any other companies – just using their stuff….

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