When choosing a screen for an ultra-short-throw projector, you may see terms such as CLR, UST ALR, ultra-short-throw ambient-light-rejecting screen, lenticular screen, and Laser TV screen.

Because different brands and retailers use different names, many buyers assume that CLR and UST ALR are two completely different screen materials.

In reality, CLR and UST ALR essentially refer to the same type of ambient-light-rejecting screen material designed for ultra-short-throw projectors.

CLR emphasizes the screen’s ability to reduce light coming from the ceiling, while UST ALR emphasizes compatibility with the unique projection path of an ultra-short-throw projector.

Quick Answer: Are CLR and UST ALR the Same?

Yes.

CLR stands for Ceiling Light Rejecting, which emphasizes the screen’s ability to reduce the impact of overhead lighting.

UST ALR stands for Ultra Short Throw Ambient Light Rejecting, which emphasizes that the screen material is designed for an ultra-short-throw projector.

Although the names focus on different features, they essentially describe the same type of screen material:

• Both are designed for ultra-short-throw projectors.

• Both receive projector light coming from below the screen.

• Both help reduce the impact of ambient light coming from above.

• Both are commonly used in living rooms and Laser TV systems.

However, this does not mean that every CLR or UST ALR product performs exactly the same.

Different screens may still vary in optical structure, gain, viewing angle, ambient-light performance, brightness uniformity, laser-speckle visibility, manufacturing quality, and installation format.

CLR vs UST ALR: Quick Comparison

Comparison	CLR	UST ALR
Full name	Ceiling Light Rejecting	Ultra Short Throw Ambient Light Rejecting
Screen category	UST ambient-light-rejecting screen	UST ambient-light-rejecting screen
Recommended projector	Ultra-short-throw projector	Ultra-short-throw projector
Projection direction	From below the screen	From below the screen
Main purpose	Receives UST projector light and reduces overhead ambient light	Receives UST projector light and reduces overhead ambient light
Basic optical application	Essentially the same	Essentially the same
What buyers should compare	Actual specifications and screen structure	Actual specifications and screen structure

What Does CLR Mean?

CLR stands for Ceiling Light Rejecting.

The term emphasizes the screen’s ability to reduce the impact of light coming from ceiling fixtures, overhead lighting, and other light sources above the screen.

A typical ultra-short-throw projector is positioned below the screen and projects the image upward at a steep angle. A CLR or UST ALR screen is designed to receive that projected light while reducing some of the unwanted light arriving from above.

UST ALR emphasizes projector compatibility, while CLR emphasizes overhead-light control.

The two terms describe the same general UST screen application from different perspectives.

Other commonly used names include:

• CLR screen

• UST ALR screen

• Ultra Short Throw ALR screen

• Ceiling-light-rejecting screen

• Lenticular UST screen

• Laser TV screen

• UST ambient-light-rejecting screen

These names may emphasize projector type, screen structure, light direction, or usage scenario. They do not necessarily represent different basic screen-material categories.

How Does a UST ALR Screen Work?

An ultra-short-throw projector is normally placed on a cabinet, tabletop, motorized tray, or floor very close to the screen.

Unlike a standard-throw or long-throw projector, it does not project directly toward the screen from several feet away. Instead, it sends light upward from below at a steep angle.

UST ALR screen material uses a directional optical structure designed to:

1. Receive projected light coming from below.

2. Reflect more of that light toward the viewing area.

3. Reduce the impact of non-projector light coming from above.

4. Help preserve perceived contrast when the room cannot be completely darkened.

This makes CLR and UST ALR screens especially useful in living rooms with ceiling lights, indirect daylight, or Laser TV systems.

They can improve daytime and lights-on viewing, but they cannot completely overcome direct sunlight shining onto the screen.

If CLR and UST ALR Are the Same Type of Material, What Actually Differs?

The meaningful differences are between individual screen products—not between the names CLR and UST ALR.

Before choosing a screen, compare the following factors.

1. Optical Structure

UST screen materials may use lenticular, sawtooth, Fresnel, or other multilayer optical structures.

Different structures may affect:

• Viewing angle

• Ambient-light control

• Brightness distribution

• Available screen sizes

• Image uniformity

• Installation options

2. Screen Gain

Screen gain affects perceived brightness in the viewing area.

A higher gain does not automatically mean better image quality. It may increase brightness, but it can also make the ideal viewing area more concentrated.

A lower-gain material may improve perceived black levels under ambient light, but it requires sufficient projector brightness.

3. Viewing Angle

Viewing angle is especially important in rooms with wide seating arrangements.

Some lenticular UST ALR materials provide a broad viewing area, while more directional optical structures may have a narrower ideal seating position.

4. Ambient-Light Performance

Room light does not come from only one direction.

Consider:

• Ceiling lights

• Side windows

• Windows behind the viewers

• Lamps near the screen

• Reflected light from pale walls and ceilings

• Direct sunlight

Even when two products are both described as UST ALR, their performance may differ under different lighting conditions.

5. Brightness, Color, and Uniformity

A darker screen surface may improve perceived black levels in a bright room, but it may also reduce overall image brightness.

The final result depends on:

• Projector brightness

• Screen size

• Screen gain

• Room lighting

• Picture mode

• Viewing position

6. Laser Speckle

Some RGB triple-laser projectors may show visible laser speckle on certain screen materials.

Speckle visibility can be affected by:

• Projector light-source design

• Screen-surface structure

• Picture content

• Viewing distance

• Screen gain

• Individual sensitivity

Buyers who are particularly sensitive to speckle should consider testing screen-material samples before purchasing.

7. Screen Design and Installation

The same general UST ALR material category can be used in:

• Fixed-frame screens

• Motorized floor-rising screens

• Motorized drop-down screens

• Recessed screens

• Laser TV cabinet systems

The best format depends on the room, available wall space, installation conditions, and whether the screen should disappear when it is not being used.

UST ALR vs Standard-Throw or Long-Throw ALR

The technically meaningful comparison is not CLR versus UST ALR.

The real difference is between UST ALR material and ALR material designed for standard-throw or long-throw projectors.

Feature	UST ALR	Standard-Throw or Long-Throw ALR
Recommended projector	Ultra-short-throw projector	Standard-throw or long-throw projector
Projector position	Very close to the bottom of the screen	Farther away and facing the screen
Projection direction	Upward from below	Toward the screen from the front
Optical orientation	Designed for steep UST light from below	Designed for more direct light from the front
Typical application	Laser TV and living-room UST theater	Media room, multipurpose space, traditional projection system
Interchangeable	Usually no	Usually no

Can Every ALR Screen Be Used with a UST Projector?

No.

ALR is a broad category. The screen material must match the projector’s throw type and projection direction.

A standard-throw or long-throw ALR screen is designed for projected light arriving more directly from the front.

When it is used with a UST projector, the screen may treat part of the projector light as unwanted light.

This can cause:

• A very dark image

• Uneven brightness

• Unusual viewing-angle performance

• Reduced contrast

• Significant brightness loss

The reverse is also true. A standard UST ALR screen is normally not suitable for a standard-throw or long-throw projector.

Does the Installation Direction of UST ALR Material Matter?

Yes. It is extremely important.

UST ALR material has a specific optical direction.

A standard version is normally designed for a projector positioned below the image. Its optical structure receives projector light from below while reducing ambient light coming from above.

A ceiling-mounted UST projector projects in the opposite direction.

A ceiling-mounted UST projector can still use UST ALR material, but the material must be installed in the reverse orientation so that the optical structure correctly receives projector light coming from above.

For a finished motorized screen, users should not dismantle and reverse the material themselves. The ceiling-mounted installation requirement should be confirmed before production or ordering.

Does Every UST Projector Require a UST ALR Screen?

Not necessarily.

A UST projector can also project onto a conventional white cinema screen. The better choice depends on the room.

Choose UST ALR when:

• The room has ceiling lights.

• There is moderate daytime ambient light.

• The projector is intended to replace a television.

• You want better perceived contrast while keeping some room lighting on.

• The projector provides enough brightness for the selected screen size.

• You need a fixed-frame, floor-rising, drop-down, recessed, or cabinet-integrated UST solution.

Consider a white cinema screen when:

• The room can be sufficiently darkened.

• Lights are normally turned off during viewing.

• You prefer a wide and uniform viewing area.

• The projector has relatively limited brightness.

• You want to compare or reduce visible laser speckle in a dark room.

A white cinema screen is compatible with UST projectors, but it does not provide the directional ambient-light control of a UST ALR screen.

How to Choose the Right UST Projector Screen

Step 1: Confirm the Projector Type

Do not assume that every laser projector is ultra short throw.

Check:

• Throw ratio

• Projection distance

• Installation diagram

• Recommended screen type

Step 2: Confirm the Projector Position

Determine whether the projector will be:

• Placed below the screen

• Installed on a motorized tray

• Positioned on the floor

• Installed above the image

• Mounted on the ceiling

This determines the required optical orientation of the screen material.

Step 3: Analyze the Room Lighting

Identify the location of:

• Ceiling lights

• Side windows

• Windows behind the viewers

• Direct sunlight

• Lamps near the screen

• Reflections from walls and ceilings

No ALR screen can completely overcome direct sunlight shining onto the image.

Step 4: Choose the Screen Size

Common UST screen sizes include:

• 100 inches

• 110 inches

• 120 inches

• 130 inches

• 150 inches

Screen size affects perceived brightness, viewing comfort, projector placement, cabinet height, throw distance, and housing dimensions.

Step 5: Choose the Installation Style

Fixed-frame screen: Suitable for rooms where permanent wall installation is acceptable.

Motorized floor-rising screen: Suitable for spaces where wall mounting is not preferred or the screen needs to be hidden after use.

Motorized drop-down screen: Suitable for wall or ceiling installation, with power supply and drop distance planned in advance.

Recessed screen: Suitable for concealed architectural installations.

Laser TV cabinet system: Integrates the projector, screen, storage, and cable management into a furniture solution.

Step 6: Compare Real Specifications

Compare:

• Compatible projector type

• Projection direction

• Optical structure

• Screen gain

• Viewing angle

• Ambient-light performance

• Brightness and color uniformity

• Laser-speckle performance

• Tension and flatness

• Screen and housing dimensions

• Installation and control methods

Common Projectors That Require a UST-Compatible Screen

Popular ultra-short-throw projector series include:

• Hisense L9Q

• Hisense PX4 Pro

• AWOL Vision UST projectors

• Epson LS800

• Formovie Theater

• XGIMI Aura 2

• Samsung LSP series

• LG CineBeam UST series

Even within the UST category, compatibility should still be confirmed according to the exact projector model, screen size, projector position, and room layout.

Suggested Internal Links

• Best Screen for Hisense L9Q

• Best Screen for Hisense PX4 Pro

• Best Screen for AWOL Vision Projectors

VIVIDSTORM Screen Selection Guide

For a UST Projector in a Living Room

When the projector is positioned below the screen and the room has ceiling lights or moderate ambient light, consider a VIVIDSTORM S PRO UST ALR screen designed for the standard bottom-up UST projection path.

A motorized floor-rising model is suitable for rooms where users do not want a permanently visible screen or do not want to drill into the wall.

For a Standard-Throw or Long-Throw Projector

Choose screen material designed for the projector’s front-facing projection angle, such as a compatible VIVIDSTORM Obsidian Long Throw ALR screen.

Do not assume that two screens are interchangeable simply because both include “ALR” in their names.

For a Dark Home Theater

When the room can be sufficiently darkened and ambient-light rejection is unnecessary, a VIVIDSTORM White Cinema screen may be the more suitable option.

Frequently Asked Questions

Are CLR and UST ALR the Same?

Yes.

CLR stands for Ceiling Light Rejecting and emphasizes reducing the impact of overhead light. UST ALR emphasizes compatibility with the projection path of an ultra-short-throw projector.

They are essentially the same type of ambient-light-rejecting screen material designed for UST projectors.

What Is the Difference Between CLR and UST ALR?

There is no fundamental difference in screen category or basic optical application.

CLR emphasizes overhead-light reduction, while UST ALR emphasizes ultra-short-throw projector compatibility.

Individual products may still differ in optical structure, gain, viewing angle, ambient-light performance, and manufacturing quality.

Is CLR Better Than UST ALR?

Not necessarily.

The name alone does not determine image quality. Buyers should compare actual optical structure, gain, viewing angle, ambient-light performance, projector compatibility, and product quality.

Is CLR the Same as Standard ALR?

Not exactly.

CLR or UST ALR refers specifically to ALR material designed for the projection path of an ultra-short-throw projector.

ALR is a broader category that may also include screens for standard-throw and long-throw projectors.

Can Every ALR Screen Be Used with a UST Projector?

No.

A UST projector requires screen material designed for steep projector light arriving from below. Standard-throw or long-throw ALR material may cause a dark or uneven image.

Can a UST ALR Screen Be Used with a Long-Throw Projector?

Usually not.

The optical directions are different. A UST ALR screen may reject or reduce projector light arriving from directly in front of the screen.

Can a UST Projector Be Used with a White Screen?

Yes.

A white cinema screen is suitable for dark or light-controlled rooms, but it does not provide the directional ambient-light control of a UST ALR screen.

Can UST ALR Eliminate All Ambient Light?

No.

It mainly reduces ambient light coming from selected directions, especially overhead lighting. It cannot completely eliminate direct sunlight or every light source in the room.

Can a Ceiling-Mounted UST Projector Use UST ALR Material?

Yes.

The UST ALR material must be installed in the reverse orientation so that its optical structure correctly receives projector light coming from above.

For a finished screen, this orientation should be confirmed during production or assembly.

Are Fresnel and Lenticular UST ALR Screens the Same?

They are designed for similar UST applications, but they use different optical structures.

As a result, they may differ in viewing angle, light control, available screen size, and installation format.

Final Conclusion

CLR stands for Ceiling Light Rejecting and emphasizes reducing ambient light coming from the ceiling.

UST ALR emphasizes compatibility with the unique projection path of an ultra-short-throw projector.

Although the names focus on different features, CLR and UST ALR are essentially the same type of ambient-light-rejecting screen material designed for ultra-short-throw projectors.

Buyers do not need to choose between two completely different technologies.

Instead, compare the actual product’s:

• Optical structure

• Gain

• Viewing angle

• Ambient-light performance

• Brightness and color uniformity

• Laser-speckle performance

• Installation format

• Compatibility with the projector and room

The most important rule is simple: the projector’s throw type and projection direction must match the optical orientation of the screen material.

Call to Action

Need Help Choosing the Right Screen?

Send VIVIDSTORM the following information:

• Projector brand and exact model

• Preferred screen size

• Projector position

• Viewing distance

• Room-light conditions

• Preferred installation style

The VIVIDSTORM team can help identify the most suitable screen material and screen structure for your setup.