APS-C sized imageLenses that create APS-C sized image are designed for digital only. They cannot be used on cameras that have image sensor larger than the APS-C format. These lenses are not suitable for film cameras either. Ultrasonic AFLenses with ultrasonic focusing mechanism tend to be quiter and faster than traditionally focusing lenses. No stepping motor AFLenses with stepping motor focusing mechanism are better for contrast based focusing, and are quiter and faster than traditionally focusing lenses. One or more Low Dispersion lens element is usedLow Dispersion lens elements help to reduce chromatic aberration. Not stabilizedImage stabilization helps to reduce blur caused by hand shake, especially at high focal length or in low light situations. Image stabilization can give 1 to 3 stop advantage over none stabilized lens, based on the reciprocal rule. Metal mountCheaper lenses are usually equipped with plastic mount, while more expensive, professional lenses have metal mount. In general, metal mounts are more durable, and a good thing to have when lenses are changed a lot. When a camera is used mainly with one lens, the material of the lens mount is not that important. Internal FocusingInternally focusing lenses don't change their size while setting focus. The front lens is fixedThe fixed front lens is not rotating during zoom and/or focusing. This allows the photographer to use petal shaped lens hood. Fixed front lenses also make the use of polarization filters a lot easier. Supports drop-in filtersDrop-in filters are used in those lenses where either the front lens is too large, or the field of view doesn't permit the use of traditional filters at the front of the lens. Usually bright tele and ultra-wide angle lenses support this filter type. |
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This autofocus circular fisheye lens has an angle of view of 180 degrees in all directions. It is exclusively designed for digital SLR cameras with the APS-C size image sensor. When used in conjunction with digital SLRs with APS-C size image sensors, it produces circular image within the frame. The F2.8 large aperture value produces a bright image in the viewfinder and allows photographers to take pictures in low light conditions, making it an ideal lens for Astrophotography and Aurora photography. Due to the quantifiable angle/area relationship it produces, this lens can be used for scientific and arts applications such as solid angle measurements of cloud distribution over the sky or vegetation distribution of the forest.
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Available mount(s) | Sigma |
Application(s) | Landscape, Interiors, Architecture, Special effects |
Category(s) | Fisheye |
Multiplier | 1.5× |
Stabilizer | no |
Focal length | 4.5 mm (prime) |
Lens construction | 13 elements in 9 groups |
Angle of view |
35mm: N/A digital: 180° |
Number of blades | 6 |
Maximum aperture | f/2.8 |
Minimum aperture | f/22 |
Minimum focusing distance | 13.5 cm |
Magnification | 0.17× |
Filter size | N/A |
Size | ∅ 76.2 × 77.8 mm |
Weight | 470 g |
Notes |
Equisolid angle projection method is possible for art and scientific use |
AF speed | N/A |
AF sound | |
Internal focusing | yes |
Internal zoom | N/A |
Fix front lens | yes |
Mount type | metal |
Weather sealed | N/A |
Drop in filter | yes |
Ultrasonic AF | yes |
Stepping motor AF | no |
APS-C sized circle | yes |
Low dispersion lens element | yes |
Hard case | N/A |
Soft case | N/A |
Lens hood | N/A |
Tripod adapter | N/A |