Additional information:
The Sigma AF 105 mm f/ 2.8 EX DG MACRO
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Diagonal angle of view 23.3°
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Minimum working distance 122 mm (90 mm with the hood)
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Max. magnification 1:1
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The front element does not rotate
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Diameter 74 mm
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Max. focal length at minimum focusing distance 154 mm
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Rotation angle of the focusing ring approx. 200°
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Width of a focusing ring 45 mm
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Minimum aperture 45 (f/32 for Nikon and Pentax and f/22 for 4/3)
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It is not compatible with Sigma 1.4x and 2.0x APO teleconverter.
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Distance information transmission(only Nikon and Sony)
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It is not equipped with a built-in motor for Nikon
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LH580-02 hood and a case included
The Sigma AF 105mm F2.8 EX DG MACRO is a full format medium telephoto macro lens, providing excellent sharpness of pictures. This lens has a plane field of the front lens and is able to take correct pictures of plane objects, both a small stamp and a big picture will be sharp from the center towards the corners. A focal length of the lens makes it possible to use an advantageous perspective for face portraits.
Switching over from AF to MF modes is realized by pulling the focusing ring 5 mm towards the camera. On the extending barrel there are two scales of distances - yellow for manual focusing and white for autofocusing. The system of Dual Focus in AF mode enables unrestricted rotation of the focusing ring without affecting the functions of autofocus. The autofocusing is slow, noisy and inaccurate.
The kit hood of the Sigma AF 105 mm f/ 2.8 EX DG MACROis threaded (58 mm) and not reversible, the kit cap is not mounted on it, but you can thread a 77 mm filter or a 77 mm cap. The filter is not shaded with the hood. It is easier to attach a 58 mm filter between the hood and the lens, sacrificing quickness of hood removal, and buy a 77 mm cap. The front element resides deep within the lens (2 cm below the front).
The lens has a focus limit switch (Full / Limit). The limit position limits the focus distance to approx. 313- 385 mm (magnification ratio from 1:1 to 1:2) to reduce autofocus hunting when shooting miniature objects.
As compared to its major competitors the Sigma AF 105 mm f/ 2.8 EX DG MACROhas the same size and weight as the Tamron 90/2.8 andis a quarter as light and short as the Canon 100/2.8. But at the minimum focusing distance both the Sigma and the Tamron grow half their size, and in this position they are longer than the Canon. With kit hoods attached at the minimum focusing distance all the three lenses have the same length.
Evaluation of Sigma designations:
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AF for autofocus.
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EX - high-quality line of lenses, combining reliability, convenience and excellent optical characteristics.
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DG - full format lens optimized for DSRL cameras, as well as for film SLR cameras.
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MACRO - macrography with the max. magnification of 1:1.
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DF (Dual Focus) - the system decouples the focusing ring from the mechanism of internal focusing when the ring is in AF mode. This system provides easy and accurate lens control, as the focusing ring does not rotate on focusing.
Links to online resources:
Posted by: dv Date of publication: 18.10.2010
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