Sigma 10-20mm f/3.5 EX DC HSM lens

The Sigma 10-20mm f/3.5 EX DC HSM lens is a popular wide-angle zoom lens designed for APS-C sensor cameras. It features a constant f/3.5 aperture throughout the zoom range, making it well-suited for low-light conditions and creative wide-angle photography. Here are the detailed specifications and features of the Sigma 10-20mm f/3.5 EX DC HSM lens:

### Key Features:

1. **Focal Length:** 10-20mm (equivalent to 16-32mm on APS-C cameras)

2. **Maximum Aperture:** f/3.5 throughout the zoom range

3. **Lens Construction:**

- Elements: 13

- Groups: 10

- Includes ELD (Extraordinary Low Dispersion), SLD (Special Low Dispersion), and aspherical lens elements to reduce chromatic aberrations and distortions

4. **Angle of View:**

- Diagonal: 102.4° - 63.8°

5. **Minimum Focusing Distance:**

- 0.24 meters (9.4 inches)

6. **Maximum Magnification Ratio:** 0.15x

7. **Filter Size:** 82mm

8. **Dimensions:**

- Diameter: 87.3mm

- Length: 88.2mm

9. **Weight:** Approximately 520 grams (18.3 ounces)

10. **Mount Compatibility:** Available for Canon EF-S, Nikon F (DX), Sigma SA, Sony/Minolta Alpha, and Pentax K mounts

11. **Diaphragm Blades:** 7, rounded for smoother bokeh

### Advanced Features:

- **DC (Digital Camera) Designation:** Optimized for APS-C sensor cameras.

- **EX (Excellence) Series:** Part of Sigma's EX series, indicating professional-grade build quality and performance.

- **HSM (Hyper Sonic Motor):** Provides fast, quiet, and accurate autofocusing with full-time manual focus override.

- **Internal Focusing System:** Ensures the lens does not extend during focusing, maintaining a consistent balance and handling.

### Image Quality:

- Delivers sharp and high-contrast images with good control of chromatic aberrations and distortions, even at wide apertures.

- The lens provides an ultra-wide focal range, making it ideal for landscapes, architecture, and interior photography.

### Build and Handling:

- Robust and durable construction, suitable for professional use.

- Features a wide zoom ring and focus ring for precise manual adjustments.

- The lens includes a built-in petal-shaped lens hood to reduce flare and protect the front element.

### Use Cases:

- **Landscape Photography:** The ultra-wide focal length allows for capturing expansive scenes.

- **Architecture Photography:** Excellent for shooting buildings and structures, both exterior and interior.

- **Interior Photography:** The wide-angle view is perfect for capturing tight spaces and interiors.

- **Creative Photography:** The wide-angle perspective can be used for creative effects and compositions.

### Compatibility:

- Designed for use with APS-C sensor cameras, providing an equivalent focal range of approximately 16-32mm.

- Not compatible with full-frame cameras without significant vignetting.

### Additional Accessories:

- **Lens Cap:** Front and rear lens caps included

- **Lens Hood:** Built-in petal-type hood included

- **Lens Case:** Soft case included for protection during transport

### Comparisons:

- Often compared to other wide-angle lenses like the Tokina 11-16mm f/2.8 AT-X116 Pro DX II and Canon EF-S 10-18mm f/4.5-5.6 IS STM.

- The Sigma 10-20mm f/3.5 EX DC HSM offers a constant f/3.5 aperture, which is an advantage in low-light conditions and for achieving a shallow depth of field compared to variable aperture lenses.

### Conclusion:

The Sigma 10-20mm f/3.5 EX DC HSM is a high-quality, ultra-wide-angle lens designed for APS-C sensor cameras. Its constant f/3.5 aperture, combined with excellent optical performance and build quality, makes it a favorite among landscape, architecture, and interior photographers. The HSM ensures quick and silent autofocusing, while the EX series designation guarantees a durable and professional build. This lens is a versatile tool for any photographer looking to expand their wide-angle capabilities.