Sigma 24-70mm f/2.8 IF EX DG HSM AF Standard Zoom Lens User Manual

1. Product Overview

This large aperture standard zoom lens covers focal lengths from 24mm to 70mm and is housed in a compact construction. It is designed for general photography including snapshots, portraiture, and landscapes. The Super Multi Layer Coating reduces flare and ghosting, while ELD (Extraordinary Low Dispersion) glass, two SLD (Special Low Dispersion) glass elements, and three aspherical lenses provide excellent correction of all types of aberrations, ensuring superior optical performance throughout the entire zoom range.

The lens incorporates HSM (Hyper Sonic Motor) for quiet and high-speed autofocus, along with full-time manual focusing capability. It features a minimum focusing distance of 38cm (15 inches) and a maximum magnification ratio of 1:5.3. The rounded 9-blade diaphragm creates an attractive background blur (bokeh).

2. Key Features

• Large Aperture Standard Zoom Lens: Constant f/2.8 aperture across the entire zoom range (24-70mm) for versatile use in various lighting conditions.
• Hyper Sonic Motor (HSM): Ensures quiet, high-speed autofocus and allows for full-time manual focus override.
• Advanced Optical Design: Features ELD (Extraordinary Low Dispersion) glass, two SLD (Special Low Dispersion) glass elements, and three aspherical lenses for excellent correction of aberrations, sharpness, contrast, and color fidelity.
• Compact and Lightweight: Approximately 30% smaller and lighter than comparable lenses from major camera manufacturers, making it easy to handle and carry.
• Close Focusing Capability: Minimum focusing distance of 38cm (15 inches) with a maximum magnification ratio of 1:5.3.
• Rounded 9-Blade Diaphragm: Produces a pleasing out-of-focus effect (bokeh) in backgrounds.
• Super Multi-Layer Coating: Suppresses flare and ghosting, ensuring high-contrast images, especially important for digital cameras.
• Inner Focusing System: Maintains constant lens length during focusing, improving balance and allowing convenient use of polarizing filters.

Figure 1: Front view of the Sigma 24-70mm f/2.8 IF EX DG HSM AF Standard Zoom Lens.

3. Setup

3.1 Attaching the Lens

1. Ensure both the camera body and the lens are clean and free of dust.
2. Align the mounting index mark on the lens with the corresponding mark on the camera body.
3. Rotate the lens clockwise (for Canon EF mount) until it clicks into place. Do not force the lens.
4. Remove the front lens cap.

3.2 Attaching the Lens Hood

The included petal-type lens hood helps to block extraneous light and reduce internal reflections, improving image quality.

1. Align the lens hood with the front of the lens.
2. Twist the hood gently until it locks securely into position.

4. Operating Instructions

4.1 Autofocus (AF) Operation

This lens is equipped with a Hyper Sonic Motor (HSM) for fast and quiet autofocus. To use autofocus:

• Set the AF/MF switch on the lens barrel to "AF".
• Ensure your camera's focus mode is set to autofocus.
• Press the shutter button halfway to activate autofocus.

4.2 Manual Focus (MF) Operation

The lens allows for full-time manual focus override even when in AF mode. To use manual focus:

• Set the AF/MF switch on the lens barrel to "MF" for dedicated manual focus, or leave it in "AF" for full-time manual override.
• Rotate the focus ring on the lens barrel to adjust focus.

4.3 Zooming

To change the focal length, rotate the zoom ring on the lens barrel to your desired setting (24mm to 70mm).

4.4 Aperture Control

The f/2.8 constant aperture provides excellent low-light performance and depth of field control. Aperture is controlled via your camera body settings.

5. Maintenance

5.1 Cleaning the Lens

• Use a soft, lint-free cloth or a lens brush to remove dust from the lens surfaces.
• For smudges or fingerprints, use a specialized lens cleaning solution and a microfiber cloth. Apply the solution to the cloth, not directly to the lens.
• Avoid touching the glass elements with your fingers.

5.2 Storage

• Always attach the front and rear lens caps when not in use.
• Store the lens in a cool, dry place, away from direct sunlight and extreme temperatures.
• If storing for extended periods, consider using a desiccant to prevent mold growth.

6. Troubleshooting

6.1 Autofocus Issues

• Lens not focusing: Ensure the AF/MF switch on the lens is set to "AF". Check camera settings to confirm autofocus is enabled.
• Slow or inconsistent autofocus: This can occur in very low light conditions. Try using manual focus or a brighter light source. Ensure the lens and camera contacts are clean.
• Back-focus or Front-focus: If images are consistently out of focus, slightly in front or behind the intended subject, your camera may require AF micro-adjustment. Refer to your camera's manual for this feature.

6.2 Image Quality Concerns

• Soft images: Ensure proper focus. Check if the lens elements are clean. Verify that the shutter speed is fast enough to prevent camera shake, especially in low light.
• Flare or ghosting: Use the included petal-type lens hood to minimize stray light. Avoid shooting directly into bright light sources.

7. Specifications

8. Warranty and Support

8.1 Warranty Information

This professional-grade Sigma EX lens is covered by a 4-year Sigma USA warranty. Please retain your proof of purchase for warranty claims.

8.2 What's in the Box

• Sigma 24-70mm f/2.8 IF EX DG HSM AF Standard Zoom Lens
• Lens Hood (Petal-type)
• Front Lens Cap
• Rear Lens Cap
• Pouch

8.3 Customer Support

For further assistance, technical support, or service, please contact Sigma Corporation of America directly. Refer to their official website for the most current contact information.