1. Introduction
The Fotodiox Pro B4 (2/3") ENG Cine Lens to Micro Four Thirds (MFT) Mount Adapter allows you to mount B4 2/3" ENG cine lenses onto Micro Four Thirds mirrorless camera bodies. This adapter provides a secure mechanical connection, enabling the use of a wide range of professional B4 lenses with MFT camera systems. It is designed for manual operation, as it does not support electronic communication between the lens and the camera body.
2. Compatibility
2.1 Compatible Camera Bodies (Micro Four Thirds Mount)
- Olympus PEN series (e.g., E-PL1, E-PL1s, E-PL2, E-PL3, E-P2, E-P3, E-M, OM-D, E-M5, E-M10)
- Panasonic Lumix DMC series (e.g., G1, G2, G3, G10, GX1, GH1, GH2, GF1, GF2, GF3, GF5, GH4)
- Panasonic AG-AF100 Mirrorless Digital Cameras
- Black Magic Pocket Cinema Camera (BMPCC)
2.2 Compatible Lenses
- B4 (2/3") ENG Cine Lenses
Important Note: This is a manual adapter. Lens functions that rely on electronic communication with the camera body (such as autofocus, automatic exposure (AE) metering, and image stabilization) will not function. All operations, including focus and aperture, must be set manually on the lens.
3. Setup
3.1 Attaching the Adapter to Your Camera
- Ensure your camera is powered off.
- Remove the rear lens cap from the adapter and the body cap from your camera.
- Align the red dot on the adapter with the corresponding red dot on your camera's lens mount.
- Insert the adapter into the camera mount and rotate it clockwise until it clicks securely into place.
Figure 1: Front view of the Fotodiox Pro B4-MFT adapter, showing the Micro Four Thirds mount side.
3.2 Attaching a B4 Lens to the Adapter
- Remove the front cap from the adapter and the rear cap from your B4 lens.
- Align the B4 lens with the adapter's B4 mount. The adapter features a 'Lock-Release' mechanism.
- Insert the lens into the adapter and rotate it until it locks into position. Ensure the lock-release mechanism engages properly for a secure fit.
Figure 2: Side view of the Fotodiox Pro B4-MFT adapter, highlighting the B4 mount side and the 'Lock-Release' mechanism.
Figure 3: A B4 ENG cine lens securely mounted onto the Fotodiox Pro B4-MFT adapter.
Figure 4: A B4 ENG cine lens with the Fotodiox Pro B4-MFT adapter attached to an Olympus Micro Four Thirds camera body.
3.3 Removing the Adapter and Lens
- To remove the lens from the adapter, press the lock-release button on the adapter and rotate the lens counter-clockwise until it detaches.
- To remove the adapter from the camera, press the camera's lens release button and rotate the adapter counter-clockwise until it detaches.
Recommendation: For heavy B4 lenses, always support the lens weight, not just the camera body, to prevent strain on the camera's lens mount.
4. Operating the Adapter
4.1 Manual Control
Since this is a mechanical adapter, all lens functions are manual:
- Focus: Adjust focus directly on the lens. The adapter supports infinity focus or beyond.
- Aperture: Adjust the aperture using the control ring on the lens. If your lens lacks a manual aperture control ring, it will default to its smallest f-stop.
4.2 Exposure Settings
To achieve proper exposure, set your camera to Aperture Priority (stop-down) mode or use Manual exposure mode. In Aperture Priority mode, the camera will meter the scene based on the manually set aperture and automatically select an appropriate shutter speed.
4.3 Potential Vignetting
Depending on the specific B4 lens attached, you may observe vignetting (darkening at the corners of the image). This adapter does not include corrective optics, which can contribute to this effect with certain lens designs.
5. Maintenance
5.1 Cleaning
- Use a clean, dry microfiber cloth to wipe the exterior of the adapter.
- Avoid using harsh chemicals or abrasive materials.
- Before initial use, thoroughly inspect and clean the interior of the adapter to remove any manufacturing residue or dust.
5.2 Storage
- When not in use, store the adapter with both front and rear caps attached to prevent dust and debris from entering.
- Store in a cool, dry place away from direct sunlight and extreme temperatures.
6. Troubleshooting
6.1 Lens Does Not Mount Securely
- Check Alignment: Ensure the lens is correctly aligned with the adapter's B4 mount.
- Verify B4 Specification: Some B4 lenses may have slight variations in their mount design. If the lens does not fit, it may be out of standard B4 specification.
- Inspect for Obstructions: Check for any debris or damage on either the lens mount or the adapter mount that might prevent a secure connection.
6.2 Image Appears Soft or Out of Focus
- Manual Focus: Ensure you are manually focusing the lens correctly. Use focus peaking or magnification features on your camera if available.
- Back Focus Adjustment: Some B4 lenses may require back focus adjustment for optimal sharpness when used with adapters. Refer to your lens's manual for instructions on adjusting back focus.
6.3 Vignetting is Visible in Images
- Vignetting can occur due to the optical characteristics of certain B4 lenses when adapted to a smaller sensor format without corrective optics. This is a normal characteristic for some lens and adapter combinations.
- Consider cropping the image in post-production if the vignetting is undesirable.
6.4 Adapter Feels Loose on Camera or Lens
- Re-mount: Detach and re-attach both the lens and the adapter, ensuring they click securely into place.
- Inspect Mounts: Check for any wear or damage on the camera mount, adapter mounts, or lens mount that could lead to a loose connection.
- Heavy Lenses: When using heavy lenses, always provide additional support to the lens itself, not just the camera body, to prevent stress on the mounts.
7. Specifications
- Product Dimensions: 3.5 x 2 x 3.5 inches
- Item Weight: 4 ounces
- Item Model Number: B4-MFT-P
- Mount Type (Camera Side): Micro Four Thirds (MFT)
- Mount Type (Lens Side): B4 (2/3") ENG Cine Lens
- Material: Precision all-metal construction with chrome plated brass mount(s)
- Features: Infinity focus, manual aperture control, sturdy build
8. Warranty and Support
For warranty information and technical support, please visit the official Fotodiox website or contact their customer service department. Keep your purchase receipt as proof of purchase.