P43 Green vs. P45 White: Which Phosphor Should You Choose for Your NVG?

Although we should speak more of phosphorescence rather than phosphorus per se; we choose to adopt the most common terminology in the night vision community.

When ordering an Image Intensifier Tube (IIT), choosing the phosphor type is the most visually impactful decision you will make. P43 delivers the iconic green image deeply embedded in tactical history, while P45 provides a crisp, modern, warm white-to-grey output.

Yet, manufacturers' spec sheets tell a clear story: within the same performance tier, raw tube metrics—such as FOM, SNR, resolution, and gain—are strictly identical. The choice does not come down to tube performance, but rather to human physiology: perception, visual comfort, and long-term cognitive strain.

An important technical point: the eyepieces are not designed to correct the chromatic aberrations of the P45 White. This is generally not a problem, but it can cause slight blurring at long distances (kilometers) compared to the P43 Green.

Voici ce que dit la science et nos expérience terrain.

The Physics of Phospors: Spectral Output and Eye Sensitivity

Here's what science and our field experience say. 

• P43 (Green-Yellow): Emits light tightly centered around 543 nm. This happens to be the exact peak of human eye sensitivity in photopic vision. Consequently, at identical luminance levels, a P43 screen will always appear brighter and more high-contrast to the human eye than a P45 screen.
• P45 (Warm White/Grey): Emits a much broader spectrum centered near 555 nm, incorporating subtle blue and red components. This output mimics a black-and-white photographic rendering, which the human brain naturally interprets as a more realistic scene.

Several large-scale clinical and military studies (notably conducted by the US Army NSRDEC in 2018 and the USMC in 2021) have demonstrated that P45 improves contrast sensitivity, thus reducing eye strain during extended missions. This contrasts with P43, which depletes the chlorolabe cones (green cones), resulting in a purple afterimage when the device is switched off. In fact, these spots persist even after the device is turned off and the ambient light returns to "normal."

On the ground: Three nights of comparative testing in the Broceliande forest

In addition to our field experiments, in January 2026, our teams conducted a two-night test protocol in the Brocéliande forest. We used two LAB-NVS systems equipped with tubes of identical specifications, the only variable being the type of phosphor. The conditions were demanding: overcast skies, no moon, and temperatures ranging from -4°C to +2°C in dense undergrowth.

Night 1: Dynamic Patrol (Comfort vs. Brightness)

At first glance, the P43 (green) tube feels noticeably brighter. Reading micro-terrain features on the forest floor is instantaneous. However, after two hours of continuous movement, visual fatigue begins to set in. Upon removing the NVG, a distinct "green afterglow" (temporary night blindness) persists in the operator's eye for roughly 30 seconds.​

The P45 (white) tube delivers a smoother, more cinematic presentation. While the brain takes a moment to calibrate to the grayscale image, the payoff is clear: after four hours of continuous patrolling, operators reported zero eye strain and no headaches.

Night 2: Static Observation (Texture Recognition vs. High Contrast)

This evolution focused on target identification and situational awareness. In terms of sheer detection distance, both phosphors perform identically. However, when it comes to identification, the P45 excels. The rich grayscale palette reveals finer details in environmental textures, such as tree bark, damp foliage, and rocks. The P43 tends to wash out these mid-tone details, favoring a starker, high-contrast image that carries less contextual data.

The Silicate System Recommendation

The global defense market reflects this shift. Since 2018, white phosphor has become the de facto standard for tier-one units worldwide, driven by advancements from industry leaders like L3Harris and Photonis. While P43 remains a highly capable tool, P45 provides the most effective, sustainable edge for the modern operator.​

NB: tubes used during both nights of testing. 

Pair n°1: NNVT NVT6 (class B) FOM1800+ P43 Green phosphor (GP) autogated and NNVT NVT6 (class B) FOM1800+ P45 White (WP) autogated

Pair n°2: NNVT NVT7 (class A/A+/S) FOM2000+ P43 Green phosphor (GP) and NNVT NVT7 (class A/A+/S) FOM2000+ P45 White phosphor (WP) autogating