Introduction
This manual provides comprehensive instructions for the setup, operation, and maintenance of your ViewSonic LS901-4K UHD 4K Laser Projector. Designed for both home theater and commercial venues, this projector delivers stunning 4K resolution with high brightness and flexible installation options. Please read this manual thoroughly before using the projector to ensure optimal performance and longevity.
Package Contents
Verify that all items listed below are included in your package:
- ViewSonic LS901-4K Laser Projector
- Power Cord
- Remote Control (with batteries)
- Quick Start Guide

Image: The contents of the projector box, including the projector unit, power cable, remote control, and quick start guide.
Setup Guide
1. Physical Placement
The ViewSonic LS901-4K projector offers flexible placement options, including table-top and ceiling mounting. Consider the desired screen size and throw distance for optimal image quality.
- Screen Size and Throw Distance: This projector can project screen sizes from 80 inches to 150 inches. For a 100-inch image, a throw distance of approximately 8.7 feet (2.6 meters) is recommended. The overall throw distance range is 7 ft to 13.1 ft (2.1m to 4m).
- Mounting: The projector is ceiling mountable. For ceiling installations, ensure proper ventilation and use a compatible mount such as the ViewSonic PJ-WMK-007.

Image: Projector distance and image size guide.

Image: Example of a ceiling-mounted projector setup.
2. Connecting Devices
Connect your video sources and other peripherals to the projector using the available ports on the rear panel.

Image: Rear panel connectivity options.
- HDMI: Two HDMI 2.0 ports with HDCP 2.2 support for connecting high-definition video sources like Blu-ray players, gaming consoles, or streaming devices.
- USB Type-A: One USB Type-A port for firmware updates or powering external devices.
- Audio Out: One 3.5mm audio output jack for connecting external speakers or audio systems.
- 12V Trigger: One 3.5mm 12V trigger port for synchronized control of motorized screens or other compatible devices.
- RS232: One RS232 port for advanced control and automation systems.
- RJ45 (Ethernet): One RJ45 Ethernet port for LAN control in commercial settings.
3. Power On/Off
Connect the power cord to the projector and a power outlet. Press the power button on the projector or the remote control to turn the unit on or off.
Operation
1. Basic Controls
The projector can be controlled using the included remote control or the control panel located on the top of the unit.

Image: Top control panel of the projector.
- Remote Control: Use the remote for full functionality, including power, source selection, menu navigation, and image adjustments.
- On-Device Controls: The top panel provides essential controls for power, source, menu navigation, and basic image adjustments, serving as a backup if the remote is unavailable.
2. Image Adjustment
Achieve a perfectly aligned and focused image using the following adjustment features:
- Optical Zoom (1.7x): Adjust the image size without moving the projector.
- Digital Zoom (0.8x-2.0x): Fine-tune the image size digitally.
- H/V Keystone Correction: Correct trapezoidal distortion when the projector is not perfectly perpendicular to the screen.
- 4-Corner Adjustment: Independently adjust each corner of the image to achieve a perfectly rectangular shape on uneven surfaces.
- Vertical Lens Shift: Shift the image vertically without tilting the projector, simplifying installation.
- 360-Degree Projection: Allows for flexible installation at any angle, including portrait mode or projecting onto a ceiling.
- Curved Screen Projection: Optimizes the image for projection onto curved surfaces.

Image: Visual representation of image adjustment features.
3. Picture Modes and Features
The LS901-4K offers various modes and features to enhance your viewing experience:
- 4K UHD Resolution (3840x2160p): Delivers crisp, detailed images.
- HDR/HLG Support: Provides enhanced contrast and vibrant colors for compatible content.
- Gaming Features: Experience smooth, high-action gaming with 4.2ms low input lag and a 240Hz refresh rate.
- Golf Mode: Specifically designed to optimize visuals for golf simulators, offering lifelike play.

Image: True 4K UHD Projector with HLG/HDR support.

Image: Golf Mode for realistic simulation.
Maintenance
Proper maintenance ensures the longevity and optimal performance of your projector.
- Laser Light Source: The LS901-4K utilizes a laser light source with a lifespan of over 20,000 hours, significantly reducing the need for lamp replacements compared to traditional projectors.
- Cleaning: Regularly clean the projector's exterior with a soft, dry cloth. For the lens, use a specialized lens cleaning cloth and solution to avoid scratches. Ensure the projector is turned off and unplugged before cleaning.
- Ventilation: Ensure the projector's ventilation openings are clear and unobstructed to prevent overheating. Do not place the projector on soft surfaces that may block airflow.

Image: Laser light source lifespan information.
Troubleshooting
If you encounter issues with your projector, refer to the following common solutions:
- No Image Displayed:
- Ensure the projector is powered on and connected to a power source.
- Verify that the video source is properly connected to the correct HDMI input.
- Select the correct input source using the remote or on-device controls.
- Check if the lens cap is removed.
- Image is Distorted or Blurry:
- Adjust the focus ring on the lens until the image is sharp.
- Use Keystone Correction and 4-Corner Adjustment to correct image shape.
- Ensure the projector is placed at an appropriate distance from the screen.
- Remote Control Not Working:
- Check and replace the batteries in the remote control.
- Ensure there are no obstructions between the remote and the projector's IR receiver.
For further assistance, please consult the full user manual available on the ViewSonic website or contact customer support.
Technical Specifications
| Feature | Specification |
|---|---|
| Model Number | LS901-4K |
| Resolution | UHD (3840x2160p) |
| Brightness | 5500 ANSI Lumens |
| Light Source | Laser |
| Light Source Lifespan | 20,000+ hours (SuperEco+ Mode: 30,000 hours) |
| Throw Ratio | 1.2-2.0 |
| Optical Zoom | 1.7x |
| Digital Zoom | 0.8x-2.0x |
| Input Lag | 4.2ms |
| Refresh Rate | Up to 240Hz |
| HDR/HLG Support | Yes |
| Keystone Correction | H/V Keystone, 4-Corner Adjustment |
| Lens Shift | Vertical |
| Projection Angle | 360-Degree |
| Connectivity | 2x HDMI 2.0, 1x USB Type-A, 1x 3.5mm Audio Out, 1x 3.5mm 12V Trigger, 1x RS232, 1x RJ45 |
| Product Dimensions (L x W x H) | 11" x 13.3" x 5.2" (27.9cm x 33.8cm x 13.2cm) |
| Item Weight | 10.69 lbs (4.85 kg) |
| Color | White |
Warranty and Support
ViewSonic offers a 3-year warranty for this product. For detailed warranty information, technical support, or to download the full user manual, please visit the official ViewSonic website:
US-based customer support is available to assist with any product-related inquiries.





