🔄 VILTROX EF-M2II 0.71× SPEED BOOSTER AF LENS ADAPTER – Canon EF to M4/3 with 1-Stop Light Boost

✅ Compatible Products

Lenses: Canon EF-mount series lenses (full-frame and APS-C compatible). Works with Canon’s extensive range of primes, zooms, and specialty lenses for photography and videography.

Cameras: Micro Four Thirds (M4/3) mount cameras (e.g., Olympus OM-D series, Panasonic Lumix G series, Blackmagic Pocket Cinema Camera 4K/6K with M4/3 mount, etc.). Enables Canon EF lenses to be mounted and used on M4/3 mirrorless cameras.

Special Functionality:

Focal Length Reduction: Multiplies the original focal length by 0.71× (equivalent focal length = focal length × 0.71), effectively widening the field of view.
Aperture Gain: Increases light intake by 1 F-stop, allowing brighter images and shallower depth of field.
Autofocus: Supports both Contrast Detection AF (CDAF) and Phase Detection AF (PDAF) modes, switchable via a dedicated adapter switch.

📦 Package Contents

Viltrox EF-M2II Lens Mount Adapter × 1

Lens Dust Cap × 1

Product Manual × 1

🔍 Product Overview

The Viltrox EF-M2II 0.71× Speed Booster AF Lens Adapter is a premium electronic adapter that expands lens compatibility by mounting Canon EF-mount lenses onto Micro Four Thirds (M4/3) cameras. Beyond simple mechanical adaptation, it incorporates advanced optics and electronics to enhance image capture:

Optical Speed Booster: Built-in 4-element, 4-group optical glass group increases incoming light by 1 F-stop and reduces the focal length to 0.71× the original, delivering a brighter image and wider effective field of view—ideal for low-light shooting and achieving shallower depth of field on M4/3 sensors.

Autofocus Modes: Choose between Contrast Detection AF (CDAF) for flexible spot focus and Eye AF (on supported cameras) or Phase Detection AF (PDAF) for faster subject acquisition with most lenses.

Firmware Updates: Update adapter firmware via USB without needing to attach a lens or camera—simply download the latest firmware from Viltrox’s official website, connect the adapter to a computer, and copy the file to the adapter’s internal memory.

Durable Construction: Precision-machined aluminum alloy with chromium plating on both mounting surfaces ensures smooth installation, secure fit, and long-term durability.

This adapter is perfect for photographers and filmmakers seeking to leverage Canon’s legendary EF lens lineup on compact M4/3 systems while gaining improved low-light performance and creative control.

✨ Key Features

0.71× Focal Length Multiplier – Wider field of view equivalent to multiplying the original focal length by 0.71.

+1 F-Stop Light Boost – Built-in optics increase light intake for brighter exposures and shallower depth of field.

4-Element, 4-Group Optics – High-quality glass group maintains image sharpness while boosting performance.

Dual AF Mode Switch:

Contrast Detection AF (CDAF): Flexible spot focus movable across the frame; supports Eye AF on compatible cameras.

Phase Detection AF (PDAF): Faster focus acquisition with most lenses (note: slower focus may occur with low-end lenses in CDAF mode).

Integrated USB Port – Firmware updates possible without attaching lens or camera; download from official website and copy file to adapter memory.

High Precision Build – Aluminum alloy with chromium-plated mounting surfaces for smooth, secure mounting and enhanced durability.

⚙️ Technical Specifications

Brand: Viltrox

Model: EF-M2II

Lens Mount: Canon EF

Camera Mount: Micro Four Thirds (M4/3)

Optical Design: 4 elements in 4 groups

Focal Length Conversion Factor: 0.71× (equivalent focal length = focal length × 0.71)

Light Increase: +1 F-stop

AF Modes: Contrast Detection AF (CDAF), Phase Detection AF (PDAF) – switchable via adapter switch

Firmware Update: Via USB port (no lens/camera attachment required)

Material: Aluminum alloy with chromium plating on mounting surfaces

Weight: Approx. [insert if available; typical ~200–250g]

Dimensions: Approx. [insert if available; compact for portability]

💡 Usage Tips

AF Mode Switching: To change AF mode, turn off the camera, remove the battery, reinsert the battery, and power the camera back on—this allows the camera to recognize the adapter as a new lens and apply the selected AF mode.

Low-End Lenses in CDAF: Expect slower focus performance with budget or older EF lenses when using CDAF mode; PDAF generally offers faster results.

Firmware Update: Download the latest firmware from Viltrox’s official website, connect the adapter to a computer via USB, and copy the firmware file to the adapter’s internal storage. Do not attach lens or camera during this process.

Lens Compatibility: While most EF lenses work, specialty lenses (extreme macros, certain tilt-shifts) may have limited electronic function; test before critical shoots.

Mounting: Align the red dot on the EF lens with the corresponding mark on the adapter and M4/3 camera body for correct orientation.

⚠️ Important Notes

No Lens/Camera Needed for Firmware Update: Firmware can be updated via USB without attaching a lens or camera—doing so with them attached may cause issues.

Focal Length & Aperture Change: The 0.71× multiplier and +1 F-stop gain are optical effects; they do not alter the lens’s physical aperture or focal length but change the effective values on the M4/3 sensor.

Focus Speed Variation: PDAF is faster on most lenses; CDAF may be slower, especially with lower-quality EF lenses.

Chromium Plating: The plating improves durability and smoothness of mounting surfaces but does not affect optical performance.