| Sigma 30mm f/1.4 EX DC HSM | |
| Key features | |
|---|---|
| Maker: | Sigma Corporation |
| Image stabilization: | No |
| Ultrasonic motor: | Yes (not available with Four Thirds, Pentax and Sony mount) |
| Short back focus: | No |
| Macro capable: | No |
| Application: | interiors/portrait |
| Technical data | |
| Focal length: | 30 mm |
| Aperture (max/min): | f/1.4 - f/16 |
| Construction: | 7 groups / 7 elements |
| # Diaphragm blades: | 8 |
| Close focus distance: | 40cm / 15.7in |
| Max. magnification: | 1:10.4 |
| Physical | |
| Max. diameter: | 75.5mm / 2.9in |
| Max. length: | 59mm / 2.3in |
| Weight: | 430g / 15.2oz. |
| Filter diameter: | 62mm |
| Accessories | |
| Lens hood: | Petal Hood |
| Angle of view | |
| Horizontal: | 43.6(1.5x), 41.1 (1.6x) |
| Vertical: | 29.9 (1.5x), 28.1 (1.6x) |
| Diagonal: | 51.4(1.5x), 48.5 (1.6x) |
| History | |
| Introduced: | 2006 |
| Retail info | |
The Sigma 30mm f/1.4 EX DC HSM is a wide-aperture photographic lens made by the Sigma Corporation, equipped with a hyper-sonic motor (HSM). The lens is produced in Canon EF mount, Four Thirds System, Nikon F-mount, Pentax K mount, the SA mount, and the Sony/Minolta AF Mount varieties, all of the same optical formula. It ships with a removable petal-type lens hood (62mm diameter). The lens assumes a crop factor of roughly 1.5, and therefore is not usable with on full-frame or 135 film cameras.
Its large aperture allows for a shallow depth of field, allowing good isolation of close subjects. On APS-C sensor cameras, its field of view equivalent to that of a 46mm lens (Nikon DX, Pentax, Sony), 48mm lens (Canon), 51mm lens (Sigma) or 60mm lens (Four Thirds). On the Four-Thirds mount, it is the only affordable normal, large aperture lens, therefore it is popular lens on that format.
The Sigma 30mm f/1.4 EX DC HSM lens has unusual optical properties. With most photographic lenses, vignetting is drastically reduced by stopping down the aperture by about 1 f-stop. This lens has a more linear response to stopping down the aperture. To reduce vignetting by about one half, it is required to stop down the aperture by over 3 full f-stops. The optical resolution properties of this lens are also unique. Most lenses are typically sharp in the center of the image frame, and softer in the edges. This problem is typically solved by stopping down the lens. This lens has little response to such an effort. When stopped down by over 4 stops, the edges of the frame are still soft. However, the center resolution of the lens is high when used wide open, and becomes exceedingly high when the lens is stopped down.[1][2]
|
|||||||||||||||||||||||||||||