1. Introduction
The VILTROX 25mm f1.7 E-Mount APS-C Auto Focus Prime Lens is a high-performance lens designed for Sony E-Mount cameras. It features a large f1.7 aperture for beautiful bokeh and excellent low-light performance, an efficient STM stepping motor for precise autofocus, and a robust optical design with 12 elements in 10 groups, including ED and aspherical lenses. Its lightweight and compact design make it ideal for various photography scenarios, from street photography to portraits.
2. Safety Information
- Do not expose the lens to extreme temperatures, humidity, or direct sunlight for prolonged periods.
- Avoid dropping or subjecting the lens to strong impacts, as this may damage internal components.
- Keep the lens caps on when not in use to protect the front and rear elements from dust and scratches.
- Do not attempt to disassemble or modify the lens. Repairs should only be performed by qualified technicians.
- When cleaning, use only lens-specific cleaning solutions and microfiber cloths to avoid damaging the coatings.
3. Product Overview
Familiarize yourself with the components of your VILTROX 25mm f1.7 lens.

Figure 3.1: The VILTROX 25mm f1.7 lens shown with its front and rear caps, lens hood, and carrying pouch.

Figure 3.2: Front view of the VILTROX 25mm f1.7 lens, highlighting the front element and focus ring.

Figure 3.3: Rear view of the VILTROX 25mm f1.7 lens, showing the E-mount interface and electronic contacts.

Figure 3.4: Close-up of the lens base, illustrating the USB-C firmware upgrade interface, electronic contacts for EXIF data transmission, and the precision hardened aluminum alloy mount.
Video 3.1: An overview of the VILTROX 25mm f1.7 STM APS-C Auto Focus Lens, showcasing its compact size, build quality, and key features. This video provides a visual unboxing and highlights the lens's design elements.
4. Setup
4.1 Attaching the Lens
- Ensure your camera is turned off before attaching or detaching the lens.
- Remove the rear lens cap from the VILTROX 25mm f1.7 lens and the body cap from your camera.
- Align the white dot on the lens barrel with the corresponding white dot on your Sony E-Mount camera's lens mount.
- Gently insert the lens into the camera mount and rotate it clockwise until it clicks into place. Do not force the lens.
- Once attached, you can remove the front lens cap.
4.2 Attaching the Lens Hood
The included lens hood helps to prevent flare and ghosting caused by stray light, and also offers physical protection to the front element.
- Align the mark on the lens hood with the mark on the front of the lens.
- Rotate the lens hood clockwise until it locks into position.
- To store, the lens hood can be reversed and attached to the lens.

Figure 4.1: The VILTROX 25mm f1.7 lens with its dedicated lens hood properly attached, ready for use.
5. Operating Instructions
5.1 Autofocus (AF) and Manual Focus (MF)
The VILTROX 25mm f1.7 lens features an STM stepping motor for fast and quiet autofocus. It also supports manual focus for precise control.
- Autofocus: Set your camera's focus mode to AF. The lens will automatically focus on your subject. The built-in STM stepping motor provides high driving force for precise autofocus and tracking focus, supporting eye/face AF for better response and lower latency.
- Manual Focus: Set your camera's focus mode to MF. Rotate the focus ring on the lens to adjust focus manually.

Figure 5.1: The lens's efficient autofocus system with eye/face detection, ensuring sharp focus on subjects.

Figure 5.2: A still frame from a video demonstrating the lens's eye-tracking autofocus capability, highlighting its precision.
5.2 Aperture Control and Bokeh
The f1.7 large aperture allows for significant control over depth of field, producing beautiful natural bokeh. The 9 aperture blades contribute to a dreamy and artistic blur effect, effectively highlighting your subject.
- Adjust the aperture setting on your camera to control the amount of light entering the lens and the depth of field.
- A wider aperture (smaller f-number like f1.7) will create a shallower depth of field, resulting in more pronounced background blur (bokeh).
- A narrower aperture (larger f-number) will increase the depth of field, keeping more of the scene in focus.

Figure 5.3: An image demonstrating the soft, pleasing bokeh produced by the f1.7 large aperture, effectively isolating the subject.

Figure 5.4: A still frame from a video illustrating the lens's ability to create beautiful background blur, making the subject stand out.
6. Maintenance
Proper maintenance will extend the life and performance of your lens.
- Cleaning the Lens: Use a blower brush to remove dust from the lens surface. For smudges or fingerprints, use a clean, soft microfiber cloth specifically designed for optics, along with a small amount of lens cleaning solution. Wipe gently in a circular motion from the center outwards.
- Cleaning the Lens Mount: Use a dry, clean cotton swab or microfiber cloth to gently wipe the electronic contacts on the lens mount. Do not touch the contacts with your fingers.
- Storage: Store the lens in a cool, dry place away from direct sunlight and high humidity. Use the provided pouch for protection when not in use.
- Firmware Updates: The lens is equipped with a micro USB interface at the bottom for convenient future firmware upgrades. Check the VILTROX official website for the latest firmware versions and instructions.
7. Troubleshooting
Common issues and their potential solutions.
| Problem | Possible Cause | Solution |
|---|---|---|
| Lens not recognized by camera | Improper attachment; dirty electronic contacts; outdated firmware. | Re-attach lens securely; clean lens and camera contacts; check for firmware updates. |
| Autofocus is slow or inaccurate | Low light conditions; subject lacks contrast; camera settings; outdated firmware. | Ensure adequate lighting; try focusing on a high-contrast area; check camera AF settings; update firmware. |
| Images are blurry | Incorrect focus; camera shake; dirty lens elements. | Verify focus; use a faster shutter speed or tripod; clean lens surfaces. |
| Lens makes unusual noises | Normal operation of STM motor; internal damage. | Slight motor sounds are normal during AF. If sounds are loud or unusual, contact support. |
If the problem persists after trying these solutions, please contact VILTROX customer support.
8. Specifications
| Feature | Detail |
|---|---|
| Brand | VILTROX |
| Model Number | 25mm f1.7 |
| Focal Length | 25mm |
| Maximum Aperture | f1.7 |
| Lens Type | Standard Prime Lens |
| Compatible Mountings | Sony E-Mount (APS-C) |
| Optical Structure | 12 elements in 10 groups (including 1 ED lens, 2 high refractive index lenses, 2 aspherical lenses) |
| Autofocus Motor | STM Stepping Motor |
| Aperture Blades | 9 |
| Product Dimensions | 2.14 x 2.52 x 2.52 inches |
| Item Weight | 6.3 ounces |
| Firmware Update Port | Micro USB |

Figure 8.1: MTF (Modulation Transfer Function) graph illustrating the lens's optical performance and a diagram showing the arrangement of its 12 elements in 10 groups, including specialized lens types.
9. What's in the Box
The VILTROX 25mm f1.7 E-Mount lens package includes the following items:
- VILTROX 25mm f1.7 Lens
- Front Lens Cap
- Back Lens Cap
- Lens Hood
- Pouch case

Figure 9.1: All items included in the VILTROX 25mm f1.7 lens package: the lens, front and back caps, lens hood, and a soft pouch.
10. Warranty and Support
VILTROX provides comprehensive support for its products. For warranty information, technical assistance, or any inquiries regarding your VILTROX 25mm f1.7 lens, please refer to the warranty card included in the box or visit the official VILTROX website. You can also find additional resources and contact information on the VILTROX Store on Amazon.

Figure 10.1: VILTROX is a competitive manufacturer in the photography equipment industry, established in 2009, committed to assisting users with their products.





