Sharper Images, Higher Transmission: Your Guide to AR Coatings for Camera Modules

Sharper Images, Higher Transmission: Your Guide to AR Coatings for Camera Modules

Anti-Reflection (AR) coatings are the unsung heroes of modern cameras, working silently to reduce reflections and boost light transmission. The result? The sharp, high-contrast images you see on your phone, in machine vision systems, and in embedded cameras. At KUPO Optics, we specialize in delivering this performance.

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Why Do AR Coatings Matter in a Camera?

Every time light passes through a glass surface—like a lens or a protective window—a small amount of it reflects away. In a compact camera module with multiple lenses, these small losses add up quickly, degrading image quality.

AR coatings solve this problem by:

• Maximizing Light to the Sensor: They slash unwanted reflections at each surface, ensuring more light makes it to the camera sensor for a brighter, cleaner image.
• Improving Detail and Contrast: By increasing the signal-to-noise ratio (SNR) and micro-contrast (MTF), AR coatings bring out fine details that would otherwise be lost.
• Reducing Ghosting and Flare: They significantly minimize the distracting glare, lens flare, and ghost images that appear around bright lights or in backlit scenes.

A typical double-sided AR coating on a camera's cover glass can boost average transmission to between 98.5% and 99.5%.

Where Are AR Coatings Used in a Camera Module?

An effective AR strategy involves coating several key components along the optical path:

• Cover Glass: This is the most critical surface. Coating both sides of the protective cover glass is the best way to maximize light throughput and prevent the most common sources of flare.
• Lens Elements: Individual lenses inside the camera assembly are often coated to prevent internal reflections.
• Filters: Components like IR-cut filters are coated to ensure they don’t introduce new reflections into the system.
• External Housings: For industrial or rugged cameras, the protective window on the main enclosure is coated to maintain image quality in harsh environments.

While coating just one side is a lower-cost option, double-sided AR coatings offer the best performance by nearly eliminating the cover glass as a source of ghost images.

Explore our [Camera Cover Glass & Windows] and [IR-Cut / NIR Filters] to learn more.

Choosing the Right AR Coating for Your Needs

The "best" AR coating is the one that meets your specific performance, durability, and cost targets.

• Single-Layer vs. Multi-Layer: A single layer of Magnesium Fluoride (MgF2​) is an economical choice for modest reflection reduction. For superior performance, multi-layer dielectric coatings offer excellent broadband reduction across the entire visible spectrum (400–700 nm) and can even be tuned for visible-near-infrared (VIS-NIR) systems.
• Field of View (FOV): Wide-angle lenses view the world from sharp angles. This Angle of Incidence (AOI) can cause color shifts at the edges of an image. We can design coatings that are optimized to maintain performance even at higher angles, minimizing these off-axis effects.
• Coating Technology: We use dense and durable sputtered AR coatings for demanding applications and cost-effective evaporated AR coatings for high-volume projects. We can also integrate specialized over-coats, like hardcoats or oleophobic (anti-smudge) layers, into the design.

For ultimate glare control, pair our AR coatings with [Black Chrome Light-Baffling] on surrounding hardware to trap stray light.

What Does High Performance Look Like?

We hold our coatings to rigorous standards to ensure they deliver in the real world. A typical high-performance AR coating for camera cover glass should achieve an average transmission (Tavg​) of 98.5% to 99.5% for light hitting at angles from 0–15°. The residual reflectance per surface is generally under 1.0%, with performance often dipping below 0.3% at key wavelengths.

We verify this performance using spectrophotometry and validate durability against industry standards like ISO 9211 (abrasion/adhesion) and MIL-C-675C (tape test). Our coatings are also proven to withstand harsh environmental conditions, including thermal cycling from −40 °C to +85 °C and 85°C/85% relative humidity soaks.

Design Tips for Flawless Images

• Eliminate Ghosts: Always opt for a double-sided AR coating on the cover glass to cut out the #1 source of internal reflections and ghosting.
• Consider Wide Angles: If your camera has a wide field of view, make sure your performance requirements include targets for higher angles (e.g., 25–30° AOI).
• Plan Your Layers: If you need a hardcoat or anti-smudge layer, let us know upfront so we can integrate it seamlessly into the coating stack.

Materials and Sizes We Support

We tailor coatings to your exact needs, not the other way around. We commonly coat:

• Aluminosilicate Glass: The standard for mobile device cover glass.
• Borosilicate & BK7 Glass: Widely used in embedded and industrial cameras.
• Sapphire: Available upon request for designs requiring extreme scratch and impact resistance.

We can handle round or square parts from 0.3 mm to 1.1 mm thick, with tight control over geometry for high-volume manufacturing.

Our Commitment to Quality

Quality means repeatable, reliable performance at scale. With KUPO, you can expect lot-by-lot testing data, cleanroom handling to prevent defects, and durable, stable films that stand up to the most demanding environments.

Learn more about our methods in our [Quality & Certifications (ISO 9211)] section.

How to Get Started with KUPO

The fastest way to a solution is to provide our team with a clear set of requirements. When you reach out, please include:

• Wavelength band (e.g., 400–700 nm)
• Angle of Incidence (AOI) or Field of View (FOV)
• Substrate material and thickness
• Durability requirements
• Quantity and project timeline

[Request a sample or custom size] today, and our team will work with you to design the perfect AR coating for your camera module.

Frequently Asked Questions (FAQ)

1) What reflectance level is good for a VIS cover glass? A target of ≤0.5–1.0% average reflectance per surface across 400–700 nm is excellent for most mobile and embedded cameras.

2) Do I need AR on both sides of the cover glass? Yes, for the best performance. Double-siding maximizes transmission to ~98.5–99.5% and is the most effective way to reduce ghost images caused by the cover glass.

3) How does a wide FOV affect AR performance? Performance can change at larger angles, but we can design the coating to minimize color shift and maintain quality across a wider field of view.

4) Will AR coatings affect my camera's color accuracy? A well-designed AR coating actually improves color accuracy by delivering more pure light to the sensor. Any minor spectral tilt is accounted for in the design.

5) What durability standards do your coatings meet? We qualify our coatings against ISO 9211, MIL-C-675C, and demanding environmental tests for temperature and humidity, based on your specific requirements.

6) Can you coat special materials like aluminosilicate or sapphire? Absolutely. We regularly coat aluminosilicate glass for mobile devices and can process sapphire for high-durability applications.