diff --git a/calibration.py b/calibration.py
index c24b025..c1c3bb9 100755
--- a/calibration.py
+++ b/calibration.py
@@ -92,7 +92,8 @@ def calibrate(input_dir: str):
     # Calculate the positions of the light sources
     light_positions = utils.lines_intersections(sphere_centers, estimated_lights)
 
-    print(estimated_lights)
+    # Calculate plane parameters from the sphere centers and intersect camera rays with the plane
+    plane_normal, plane_alpha = utils.plane_parameters_from_points(sphere_centers)
 
     # Return value as dictionnary
     return {
@@ -102,6 +103,10 @@ def calibrate(input_dir: str):
             'directions': estimated_lights[i].tolist(),
         } for i, (name, position) in enumerate(zip(image_names, light_positions))],
         'spheres': sphere_centers.tolist(),
+        'plane': {
+            'normal': plane_normal.tolist(),
+            'alpha': plane_alpha.tolist(),
+        }
     }
 
 
@@ -115,8 +120,6 @@ def main():
     with open('data/calibration.json', 'w') as f:
         json.dump(calib, f, indent=4)
 
-    print(calib)
-
 
 if __name__ == '__main__':
     main()
diff --git a/templates/calibration.html b/templates/calibration.html
index b785b26..f0e20fa 100644
--- a/templates/calibration.html
+++ b/templates/calibration.html
@@ -22,10 +22,18 @@
             </div>
         </div>
         <div>
-            <label class="checkbox">
-                <input type="checkbox" id="show-lines">
-                Afficher les droites
-            </label>
+            <div>
+                <label class="checkbox">
+                    <input type="checkbox" id="show-lines">
+                    Afficher les directions de la lumière pour chaque sphère
+                </label>
+            </div>
+            <div>
+                <label class="checkbox">
+                    <input type="checkbox" id="show-plane">
+                    Afficher le plan contenant les sphères
+                </label>
+            </div>
         </div>
     </div>
 </section>
diff --git a/ts/Calibration.ts b/ts/Calibration.ts
index e7d418c..49a5dc6 100644
--- a/ts/Calibration.ts
+++ b/ts/Calibration.ts
@@ -17,6 +17,17 @@ export interface Led {
     directions: Vector3[];
 }
 
+/**
+ * A 3D plane.
+ */
+export interface Plane {
+    /** The normal of the plane. */
+    normal: Vector3;
+
+    /** The offset of the plane. */
+    alpha: number;
+}
+
 /**
  * Type for the calibration data.
  */
@@ -26,4 +37,7 @@ export interface Calibration {
 
     /** Position of the spheres. */
     spheres: Vector3[];
+
+    /** The coordinates of the plane that best fit the spheres. */
+    plane: Plane;
 }
diff --git a/ts/CameraObject.ts b/ts/CameraObject.ts
index 3ab834c..cc24c89 100644
--- a/ts/CameraObject.ts
+++ b/ts/CameraObject.ts
@@ -31,7 +31,7 @@ export default class CameraObject extends THREE.Object3D {
 
         // Faces
         {
-            let material = new THREE.MeshPhongMaterial({color: 0xffffff});
+            let material = new THREE.MeshPhongMaterial({color: 0x00ff00});
             material.transparent = true;
             material.opacity = 0.8;
 
@@ -117,7 +117,7 @@ export default class CameraObject extends THREE.Object3D {
      */
     hover(): void {
         this.mesh.material.opacity = 1;
-        this.lines.material.color.setHex(0xff0000);
+        this.lines.material.color.setHex(0xffffff);
     }
 
     /**
@@ -125,7 +125,7 @@ export default class CameraObject extends THREE.Object3D {
      */
     unHover(): void {
         this.mesh.material.opacity = 0.8;
-        this.lines.material.color.setHex(0x990000);
+        this.lines.material.color.setHex(0x999999);
     }
 
 }
diff --git a/ts/Engine.ts b/ts/Engine.ts
index 9a31eba..8abf411 100644
--- a/ts/Engine.ts
+++ b/ts/Engine.ts
@@ -46,12 +46,15 @@ export class Engine {
     /** HTML element on which the renderer will be added. */
     domElement: HTMLElement;
 
-    /** Checkbox indicating whether wants to show the lines from the spheres to the lights. */
+    /** Checkbox indicating whether the user wants to show the lines from the spheres to the lights. */
     showLinesCheckbox: HTMLInputElement;
 
     /** HTML span where we will show the name of the current selected led. */
     selectedObject: HTMLElement;
 
+    /** HTML element indicating whether the user wants to show the plane containing all spheres. */
+    showPlaneCheckbox: HTMLInputElement;
+
     /** HTML image where we will show the real photo corresponding to the selected led. */
     ledView: HTMLImageElement;
 
@@ -73,6 +76,9 @@ export class Engine {
     /** Object containing all the representations of the spheres (white). */
     spheres: THREE.Object3D;
 
+    /** The plane that approximates the plane containing the spheres. */
+    plane: THREE.Mesh<THREE.PlaneGeometry, THREE.MeshPhongMaterial>;
+
     /** Axes that will be shown to help the visualisation of the scene. */
     axes: THREE.AxesHelper;
 
@@ -123,6 +129,7 @@ export class Engine {
      */
     initHtml(): void {
         this.showLinesCheckbox = getInputElementById('show-lines');
+        this.showPlaneCheckbox = getInputElementById('show-plane');
         this.selectedObject = getElementById('selected-object');
         this.ledView = getImageElementById('led-view');
     }
@@ -152,10 +159,17 @@ export class Engine {
         }
         this.scene.add(this.spheres);
 
+        let normal = new THREE.Vector3(-calibration.plane.normal[1], -calibration.plane.normal[0], calibration.plane.normal[2]);
+        this.plane = new THREE.Mesh(new THREE.PlaneGeometry(20, 20), new THREE.MeshPhongMaterial({ color: 0x0000ff, side: THREE.DoubleSide, transparent: true, opacity: 0.5 }));
+        this.plane.lookAt(normal);
+        this.plane.position.set(0, 0, -calibration.plane.alpha / calibration.plane.normal[2]);
+        this.plane.visible = this.showPlaneCheckbox.checked;
+        this.scene.add(this.plane);
+
         this.axes = new THREE.AxesHelper(10);
         this.scene.add(this.axes);
 
-        this.ambientLight = new THREE.AmbientLight(0xffffff, 0.15);
+        this.ambientLight = new THREE.AmbientLight(0xffffff, 1);
         this.scene.add(this.ambientLight);
 
         this.renderer = new THREE.WebGLRenderer({antialias: true, alpha: true});
@@ -186,6 +200,7 @@ export class Engine {
         window.addEventListener('pointermove', (e) => this.onPointerMove(e));
         window.addEventListener('pointerup', () => this.onPointerUp());
         this.showLinesCheckbox.addEventListener('change', () => this.leds.setShowLines(this.showLinesCheckbox.checked));
+        this.showPlaneCheckbox.addEventListener('change', () => this.plane.visible = this.showPlaneCheckbox.checked);
         document.addEventListener('keyup', (e) => {
             switch (e.code) {
                 case "ArrowDown":
diff --git a/ts/Led.ts b/ts/Led.ts
index a857bb9..774687a 100644
--- a/ts/Led.ts
+++ b/ts/Led.ts
@@ -56,7 +56,7 @@ export class Led extends THREE.Mesh<THREE.SphereGeometry, THREE.MeshBasicMateria
         this.lines.visible = false;
         this.add(this.lines);
 
-        this.light = new THREE.PointLight(0xffffff, 100);
+        this.light = new THREE.PointLight(0xffffff, 1000);
         this.light.visible = false;
         this.add(this.light);
     }
diff --git a/utils.py b/utils.py
index a95742b..b0aaf70 100644
--- a/utils.py
+++ b/utils.py
@@ -505,3 +505,20 @@ def estimate_light(normals, grey_levels, treshold=(0, 1)):
     validity_mask = np.logical_and(grey_levels > treshold[0], grey_levels < treshold[1])
     lights = weighted_least_squares(normals, grey_levels, validity_mask)
     return lights
+
+
+def plane_parameters_from_points(points):
+    """Computes the parameters of a plane from a set of points.
+
+    Args:
+        points (Array ..., dim): Coordinates of the points used to define the plane.
+
+    Returns:
+        Array ..., dim: Normal vector to the plane.
+        Array ...: Plane constant alpha.
+    """
+    homogeneous = to_homogeneous(points)
+    E = np.einsum('...ki,...kj->...ij', homogeneous, homogeneous)
+    L = matrix_kernel(E)
+    n, alpha = L[..., :-1], L[..., -1]
+    return n, alpha