The Sigma AF 4.5mm F2.8 EX DC Circular Fisheye HSM
angle of view 180°
Diameter 76.2 mm
max. magnification 1:6
minimum working distance 1.9 cm (19 mm)
The Sigma AF 4.5mm F2.8 EX DC Circular Fisheye HSM is a fast superwide-angle lens of the circular fisheye type with an HSM autofocus drive. It has been specially designed for small-format digital SLR cameras and cannot be used on full-format and film cameras.
The optical scheme of the lens includes one SLD element in the rear group made of super low dispersion glass for correction of chromatic aberration. The super multi-coating optimized for digital cameras decreases flare and halation, and corrects color rendering. The hyper-sonic motor AF drive provides noiseless and high-speed autofocusing with the possibility of full-time manual focusing without switching to the manual mode. The lens has an internal focusing.
The Circular Fisheye produces a circular 12.3 mm image with an angle of view of 180° at the center with a black surrounding frame. An image like that is beyond human eye's ability, but can be successfully used in photography. The lens has a very large depth of field.
A very large angle of view does not make it possible to use screw mount filters. Filters are attached to the rear of the lens. A gelatin filter holder and 72 mm cap adapters are completed with the lens.
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Posted by: dv Date of publication: 01.11.2010