The Sigma 120-400 F4.5-5.6 is widely regarded as the 2nd choice for both Canon and Nikon shooters. It is viewed as the cheaper alternative to the Canon 100-400L IS and the Nikon 80-400 VR. This lens has 21 elements in 15 groups. 3 of those 21 elements, are special SLD( Special Low Dispersion) glass to minimize flare and ghosting. It comes with Sigma's Optical Stabilizer( OS) which according to Sigma, gives stabilization to 4 stops. It also comes with a HSM which means that it has quick, quiet and accurate AF. It is compatible with lower end Nikon bodies, such as the D3000, D5000, D5100 and D3100. The minimum focus distance of this lens is 1.5m. In this review, I will see how this lens performs. This review will be split into 2 parts
1st test: Sharpness
* Note camera is mounted on tripod and mirror lock up is being used to minimize shake and OS is OFF. Focus with live view.
At 120mm
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| f 4.5 |
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| F 5.6 |
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| F 8 |
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| F16 |
At 200mm
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| F 5.3 |
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| F 5.6 |
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| F 8 |
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| F 16 |
At 300mm
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| F 5.6 |
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| F 8 |
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F 16
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At 400mm
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| F 5.6 |
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F 8
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400 at F/16 turned out too soft to show. As you can see from above, this particular copy of the 120-400 is pretty sharp. It is especially sharp where it matters at 400. The result at 5.6 is not bad but stopping it down to F8 really pumps out some quality results. Generally, for this lens, anything past F8, results in diffraction making the image soft.
OS effectiveness
This being a telephoto lens, Image stabilization is critical. Sigma claims this lens's inbuilt stabilization, allows for 4 stops of compensation. Lets see.
* Note. Minimum shutter speed for a 400mm lens for all shots to be shake free is 1/400. IS will NOT guarantee a shake free picture below 1/400 but will increase the chances. IS will also not help freeze action.
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| OS off( 1/1000) |
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OS on( 1/200)
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These shots were taken consecutively at 400mm f/5.6. Other shots at 1/100 and 1/125, appeared blur. The OS in this lens is not as good as Sigma claims it is but its still provides a good 2.5 stops of compensation.
End of part 1. Part 2 will be continued on the next post. Part 2 will cover distortion, vignetting, aberrations and build quality.
