Can I use a short-throw projector designed for less than 120 inches to project a 150-inch image?

The drawbacks: Insufficient brightness, grayish colors, and obvious pixelation.

Pushing the Limits: The Pitfalls of Over-projecting with a Short-Throw Projector

Short-throw projectors have revolutionized home theaters and office presentations by allowing for large images from a very short distance. Their convenience is undeniable. However, like all optical instruments, they are designed with specific limits. Pushing a short-throw projector rated for a maximum of 120 inches to project a massive 150-inch screen might seem like a clever hack, but it comes with significant compromises that degrade the viewing experience.

Here are the primary drawbacks you will encounter:

1. The Great Dimming: Drastic Loss of Brightness

This is the most immediate and noticeable problem. Projector brightness is measured in lumens. A projector's light engine and lamp/LED are calibrated to illuminate a specific surface area—in this case, a 120-inch diagonal screen.

When you expand the image to 150 inches, you are increasing the total projection area by over 50%. The same fixed amount of light must now be spread over this much larger canvas. This results in a dimmer, washed-out image. Colors will lose their vibrancy, and black levels will appear gray. The image will only be viewable in a completely dark room, and even then, it will lack the "pop" and dynamic range the projector was intended to deliver at its recommended size.

2. Soft Focus and Loss of Sharpness

Projector lenses are engineered to resolve detail optimally within their designed throw ratio. To make the image larger from the same distance, the projector's internal optics must be adjusted, often by digitally scaling the image and shifting lens elements.

This process pushes the lens beyond its optimal performance zone. The result is a noticeable softness or blurriness across the entire image. Fine details in text, facial features, and on-screen graphics will be lost. No amount of manual focusing will be able to achieve the crisp, sharp picture you would get at the native 120-inch size, as you are fighting the fundamental limits of the lens's design.

3. Compromised Color Accuracy and Uniformity

Modern projectors use complex algorithms to ensure color and brightness are consistent from the center of the image to its edges—a quality known as uniformity. When you over-project, this delicate balance is disrupted.

You will likely notice that the corners and edges of your 150-inch image are even dimmer than the center (a phenomenon called vignetting). Color shifting may also occur, where colors look different at the edges of the screen compared to the center. The overall color calibration, carefully set by the manufacturer for the intended screen size, will be thrown off.

4. Exaggerated Pixel Structure and Screen Door Effect

Every projector has a native resolution (e.g., 1080p or 4K), made up of tiny pixels. By stretching the image, you are also physically stretching the gaps between these pixels. This makes the pixel grid more visible, a flaw known as the "screen door effect," where it feels like you are watching the image through a fine mesh screen. This is particularly distracting with high-definition content, defeating the purpose of a large, immersive experience.

5. Increased Visibility of Flaws and Artifacts

At its intended size, a projector's image processing effectively handles noise and digital artifacts. However, when the image is stretched, every minor flaw is magnified. Source noise from low-bitrate streaming, compression artifacts, and any dust on the lens or internal components becomes more pronounced and distracting.

The Bottom Line: A Compromise, Not an Upgrade

While it is technically possible to project a 150-inch image with a sub-120-inch short-throw projector, the result is a shadow of the device's true capability. You are trading a bright, sharp, and vibrant image for a larger, but dim, soft, and inconsistent one.

For a truly satisfying 150-inch cinematic experience, the correct solution is to invest in a projector specifically designed and rated for that size. By matching your projector to your screen, you ensure that every lumen of brightness and every pixel of detail is used to its fullest potential, delivering the immersive impact you're looking for.

SCREEN PRO offers a series of professional 150” giant screen options.