1. Introduction
Thank you for choosing the Viltrox AF 25MM F1.7 APS-C Lens. This high-quality autofocus prime lens is designed for APS-C mirrorless cameras, offering a versatile 25mm focal length (approximately 38mm full-frame equivalent) and a bright F1.7 maximum aperture. It is ideal for a wide range of photography, including street, still life, environmental portraits, and general-purpose shooting, delivering excellent image quality with true-to-life color reproduction and sharp focus.
2. Package Contents
Please check that all items are present in your package:
- Packing box
- Viltrox AF 25MM F1.7 APS-C Lens
- Carrying pouch
- Lens hood
- Rear lens cap
- Front lens cap
- User manual (this document)
- Warranty Card

3. Setup
3.1 Attaching the Lens to Your Camera
- Ensure your camera is turned off.
- Remove the rear lens cap from the Viltrox AF 25MM F1.7 lens and the body cap from your camera.
- Align the mounting index (white dot) on the lens with the corresponding index on your camera body.
- Insert the lens into the camera mount and rotate it clockwise until it clicks into place. Do not force the lens.

3.2 Detaching the Lens from Your Camera
- Ensure your camera is turned off.
- While pressing the lens release button on your camera body, rotate the lens counter-clockwise until it stops.
- Gently remove the lens from the camera body.
- Attach the rear lens cap to the lens and the body cap to your camera to protect them from dust and damage.
3.3 Attaching the Lens Hood
The included lens hood helps to block stray light, reducing flare and ghosting, and provides some physical protection for the front element of the lens.
- Align the mark on the lens hood with the mark on the front of the lens.
- Twist the hood clockwise until it locks into place.

4. Operating Instructions
4.1 Autofocus (AF) Operation
This lens supports autofocus (AF) functionality. Once mounted on a compatible camera, the camera's AF system will control the lens's focus. Refer to your camera's instruction manual for specific AF mode settings and operation.
4.2 Aperture Control
The aperture (F-number) of this lens is controlled electronically through your camera body. You can adjust the aperture settings directly on your camera to achieve desired depth of field and exposure. The lens features a maximum aperture of F1.7 for excellent low-light performance and shallow depth of field, and a minimum aperture of F16.0.
4.3 General Usage
- **Photography Modes:** Use your camera's various photography modes (e.g., Aperture Priority, Shutter Priority, Manual) to control exposure settings in conjunction with the lens.
- **Focusing Distance:** The lens has a minimum focusing distance of 0.3m/1ft.
- **Filter Thread:** The front of the lens has a ⌀52mm filter thread for attaching compatible filters (e.g., UV, CPL, ND).

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 stubborn smudges or fingerprints, use a lens cleaning solution specifically designed for optical elements and a clean microfiber cloth. Apply the solution to the cloth, not directly to the lens.
- Never use abrasive materials, solvents, or harsh chemicals to clean the lens.
5.2 Storage
- Always attach the front and rear lens caps when the lens is not in use.
- Store the lens in a cool, dry place, away from direct sunlight and extreme temperatures.
- If storing for an extended period, consider using a dehumidifying agent to prevent mold growth.
6. Troubleshooting
6.1 Lens Not Focusing
- Ensure the lens is securely mounted to the camera body.
- Check your camera's focus mode settings. Make sure it's set to autofocus (AF) if you intend to use the lens's AF capabilities.
- Verify that there is sufficient light for the camera's autofocus system to operate effectively.
- Clean the lens contacts on both the lens and camera body with a clean, dry cloth.
6.2 Image Quality Issues (e.g., Softness, Aberrations)
- Ensure the lens and camera sensor are clean. Dust or smudges can significantly impact image quality.
- Check your camera's shutter speed and ISO settings to avoid motion blur or excessive noise.
- For optimal sharpness, consider shooting at apertures slightly stopped down from the maximum (e.g., F2.8 or F4 instead of F1.7).
- Verify that the lens is compatible with your camera model and that the camera's firmware is up to date.
7. Specifications
| Feature | Specification |
|---|---|
| Brand Name | Viltrox |
| Focal Length | 25mm |
| Maximum Aperture | F1.7 |
| Minimum Aperture | F16.0 |
| Number of Diaphragm Blades | 9 Blades |
| Focus Mode | AF (Autofocus) |
| Focus Type | Standard Prime |
| Lens Type | Automatic |
| Type | Fixed Focus Lens |
| Full Frame | No (Designed for APS-C) |
| Applicable Camera Specifications | APS-C Mirrorless Camera |
| Filter Thread Size | ⌀52mm |
| Minimum Focusing Distance | 0.3m / 1ft |
| Optical Structure | 9 groups, 11 elements (including 2 Aspherical, 1 ED low-dispersion, 2 high refractive index elements) |
| High-concerned chemical | None |
| Origin | Mainland China |


8. User Tips
- **Experiment with Aperture:** The F1.7 aperture allows for beautiful background blur (bokeh). Practice shooting at various apertures to understand how depth of field changes and use it creatively.
- **Low Light Performance:** Utilize the wide F1.7 aperture for excellent performance in low-light conditions, allowing for faster shutter speeds and lower ISO settings.
- **Prime Lens Advantage:** As a fixed focal length (prime) lens, it encourages you to 'zoom with your feet' by moving closer or further from your subject, which can enhance your compositional skills.
- **Lens Hood Usage:** Always use the lens hood, especially in bright conditions, to minimize lens flare and protect the front element from accidental bumps.
9. Warranty and Support
For warranty information, please refer to the warranty card included in your package. For technical support, firmware updates, or additional resources, please visit the official Viltrox website or contact their customer service. A detailed user manual in PDF format may also be available for download on the manufacturer's website.
Note: The PDF user manual can be found at: Viltrox AF 25MM F1.7 APS-C Lens PDF Manual





