SIRUI IronStar 45mm T1.9 1.5X Anamorphic Cine Lens User Manual

1. Product Overview

The SIRUI IronStar 45mm T1.9 1.5X Anamorphic Cine Lens is designed for full-frame cameras, offering a distinctive cinematic widescreen aspect ratio with a constant 1.5x anamorphic squeeze. It features a fast T1.9 aperture for excellent low-light performance and shallow depth of field, along with an interchangeable mount system for broad camera compatibility.

Key Features

• Cinematic Widescreen Capture: Achieves a 2.39:1 widescreen aspect ratio on full-frame cameras with a 1.5x anamorphic squeeze.
• Exceptional Low-Light Performance: Fast T1.9 maximum aperture for bright, clear images and shallow depth of field.
• Universal Camera Compatibility: Features an interchangeable mount system with native PL and user-interchangeable EF mounts.
• Outstanding Image Quality: Delivers sharpness across the frame with distinctive bokeh, controlled flaring, and minimal focus breathing.
• Precision Optical Engineering: Utilizes aspherical and cylindrical lens elements for high-resolution visuals and reduced chromatic aberration.
• Professional Cine-Standard Build: 95mm front diameter and 0.8 MOD focus and iris gears for compatibility with standard cinema equipment.

Figure 1: Illustration of the 1.5X Constant Squeeze Ratio, demonstrating wider horizontal view and elliptical bokeh for cinematic effects.

Figure 2: Visual representation of the T1.9 fast aperture, highlighting sharp performance in low-light shooting and shallow depth of field.

2. Getting Started

2.1 What's in the Box

• SIRUI IronStar 45mm T1.9 1.5X Anamorphic Cine Lens (with PL Mount pre-installed)
• EF Mount Module
• Front Cap
• Back Cap
• U-Shaped Wrench
• L-Shaped Allen Key
• Screwdriver
• PL, EF Shims (various thicknesses)
• Lens Cleaning Cloth
• Tool Box

2.2 Interchangeable Lens Mount Replacement

The SIRUI IronStar lens features an interchangeable mount system, allowing you to switch between PL and EF mounts. Follow these steps to replace the lens mount:

1. Open the lens back cap.
2. Take out the U-shaped wrench. Align the wrench with the two holes on the mount and rotate counterclockwise to remove the cover.
3. Take out the Allen key and unscrew the four screws securing the current lens mount.
4. Carefully remove the lens mount.
5. Select the desired new lens mount (e.g., EF mount) and align it with the threaded holes on the lens.
6. Insert each screw into its hole and tighten securely.
7. Mount the cover back on by aligning the wrench and rotating clockwise.

Figure 3: Visual guide for replacing the interchangeable PL/EF lens mount.

2.3 Back Focus Adjustment

Proper back focus adjustment is crucial for achieving sharp images. This lens features an innovative integrated back focus system that allows adjustment without disassembly or shims.

1. Mount the camera and lens on a tripod.
2. Place a focus subject (e.g., a test chart) at a distance of 1 meter from the camera sensor.
3. Turn the lens's focus ring to the 1-meter position.
4. Observe the subject on your camera's monitor. If the subject is blurry, it is necessary to adjust the back focus.
5. Loosen the small screw on the back focus adjustment ring.
6. While observing the subject on the monitor, rotate the back focus ring until the subject appears sharp.
7. Tighten the screw on the back focus adjustment ring.
8. Recheck the focus. If the focus scale matches the actual distance, the adjustment is successful. If the focus ring reads more than 1 meter, remove shims. If it reads less, add shims.

Figure 4: The innovative back focus adjustment ring allows for precise calibration without shims or complex disassembly.

3. Operation

3.1 Manual Focus

The IronStar 45mm lens is a manual focus lens. Rotate the focus ring to achieve sharp focus on your subject. The lens features dual focus distance units (meters and feet) for precise control. The 270° focus throw allows for smooth and accurate focus pulls.

3.2 Aperture Control

Adjust the aperture ring to control the depth of field and exposure. The lens offers a fast T1.9 maximum aperture for low-light conditions and a shallow depth of field, creating a cinematic look with blurred backgrounds. The aperture can be stopped down to T16 for increased depth of field.

3.3 Cinematic Effects

This anamorphic lens produces distinctive oval bokeh and controlled lens flares, contributing to a unique cinematic aesthetic. The neutral flare option provides a subtle touch, ideal for various shooting scenarios.

Figure 5: Comparison of Classic Blue Flares and Natural Flares, demonstrating the lens's ability to produce subtle yet cinematic light effects.

4. Maintenance

4.1 Cleaning the Lens

• Use a blower brush to remove dust and loose particles from the lens surface.
• For smudges or fingerprints, apply a small amount of lens cleaning solution to a clean microfiber cloth (provided) and gently wipe the lens in a circular motion from the center outwards.
• Avoid using abrasive materials or harsh chemicals, as these can damage the lens coatings.

4.2 Storage

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

5. Troubleshooting

5.1 Blurry Images

• Check Focus: Ensure the lens is properly focused on your subject. As a manual focus lens, precise adjustment is required.
• Adjust Back Focus: If images consistently appear soft or out of focus despite careful manual focusing, the back focus may need adjustment. Refer to Section 2.3 for detailed instructions on how to perform back focus adjustment.
• Verify Shims: If back focus adjustment using the ring is insufficient, you may need to add or remove shims. Refer to the back focus adjustment video (Video 3) for guidance on shim-based adjustment.

5.2 Lens Mount Issues

• Mount Not Secure: Ensure all screws are tightened securely after changing the lens mount.
• Incorrect Mount: Verify that the correct mount (PL or EF) is installed for your camera system.

6. Specifications

Figure 6: Detailed specifications for the SIRUI IronStar 45mm T1.9 1.5X Anamorphic Cine Lens.

7. Warranty and Support

SIRUI products are manufactured to high-quality standards. For warranty information, please refer to the warranty card included with your product or visit the official SIRUI website. If you encounter any issues or require technical assistance, please contact SIRUI customer support through their official channels.

Online Support: Visit the Sirui Store on Amazon or the official SIRUI website for FAQs, support resources, and contact information.