diff --git a/src/render/cesium/appRenderer.test.mjs b/src/render/cesium/appRenderer.test.mjs
index c0f6eaf05..2c565a710 100644
--- a/src/render/cesium/appRenderer.test.mjs
+++ b/src/render/cesium/appRenderer.test.mjs
@@ -333,8 +333,6 @@ const EXPECTED_MISSING = [
   'camera.controls.suspend',
   'camera.controls.zoomFactor',
   'camera.controls.zoomInputs',
-  'camera.matrices',
-  'camera.setFov',
   'draw.atlas',
   'draw.clampState',
   'draw.on',
diff --git a/src/render/cesium/camera.js b/src/render/cesium/camera.js
index d61f1bc53..75a64debc 100644
--- a/src/render/cesium/camera.js
+++ b/src/render/cesium/camera.js
@@ -91,7 +91,10 @@ export function createCesiumCamera({ scene, camera, report, widget }) {
     report,
   });
   removers.push(
-    scene.postUpdate.addEventListener(() => cameraEvents.stepChanged()),
+    scene.postUpdate.addEventListener(() => {
+      applyFov();
+      cameraEvents.stepChanged();
+    }),
     camera.moveStart.addEventListener(() => cameraEvents.emit('moveStart')),
     camera.moveEnd.addEventListener(() => cameraEvents.emit('moveEnd')),
   );
@@ -176,6 +179,23 @@ export function createCesiumCamera({ scene, camera, report, widget }) {
     return handle;
   }
 
+  /**
+   * The vertical field of view `setFov` asked for, held across resizes:
+   * Cesium's `fov` is the wider of the two angles (the horizontal one when
+   * the view is wider than tall), and it keeps that one when the aspect
+   * changes. Before the first resize, and on a frustum without a field of
+   * view, it waits.
+   */
+  let heldFovy = null;
+  function applyFov() {
+    const frustum = camera.frustum;
+    const aspect = frustum?.aspectRatio;
+    if (heldFovy === null || !('fov' in frustum) || !(aspect > 0)) return;
+    const fov =
+      aspect > 1 ? 2 * Math.atan(Math.tan(heldFovy / 2) * aspect) : heldFovy;
+    if (frustum.fov !== fov) frustum.fov = fov;
+  }
+
   const cameraPort = {
     on: (event, cb, options) => cameraEvents.on(event, cb, options),
     onCommand: (cb) => commandHooks.on(cb),
@@ -288,6 +308,24 @@ export function createCesiumCamera({ scene, camera, report, widget }) {
       else camera.zoomIn(metres);
       scene.requestRender();
     },
+    setFov({ vertical }) {
+      // Cesium would take a bad angle and draw a garbage projection.
+      if (!(vertical > 0 && vertical < Math.PI))
+        throw new RangeError(`no vertical field of view of ${vertical}`);
+      heldFovy = vertical;
+      applyFov();
+      scene.requestRender();
+    },
+    // The scene's own frame: ECEF in 3D, the only mode Core runs (Cesium's
+    // 2D and Columbus view frames are projected map coordinates).
+    matrices() {
+      return {
+        view: Float64Array.from(Cesium.Matrix4.toArray(camera.viewMatrix)),
+        projection: Float64Array.from(
+          Cesium.Matrix4.toArray(camera.frustum.projectionMatrix),
+        ),
+      };
+    },
     viewRectangle() {
       const rect = camera.computeViewRectangle(Cesium.Ellipsoid.WGS84);
       if (!rect) return null;
diff --git a/src/render/cesium/cameraPort.test.mjs b/src/render/cesium/cameraPort.test.mjs
index a12572d26..efd9f73a9 100644
--- a/src/render/cesium/cameraPort.test.mjs
+++ b/src/render/cesium/cameraPort.test.mjs
@@ -25,7 +25,7 @@ const QUERY_RECORDS = new Set([
   'occluded',
 ]);
 /** Commands and records the port does not have yet. */
-const MISSING = new Set(['matrices']);
+const MISSING = new Set([]);
 
 const runnable = CAMERA_SCRIPTS.filter((script) =>
   script.steps.every(
@@ -232,3 +232,21 @@ test('a Cesium viewer with no renderer bound gets a camera port over its own cam
     assert.throws(() => cameraOf({ scene, camera: {} }), /no renderer camera/);
   });
 });
+
+test('setFov holds the vertical angle across resizes, and waits for a first one', () => {
+  const { scene, camera } = headlessCamera();
+  scene.postUpdate = new Cesium.Event();
+  scene.requestRender = () => {};
+  camera.frustum.aspectRatio = NaN;
+  const { port } = createCesiumCamera({ scene, camera, report: () => {} });
+  port.setFov({ vertical: 0.5 });
+  for (const aspect of [16 / 9, 0.6, 4 / 3]) {
+    camera.frustum.aspectRatio = aspect;
+    scene.postUpdate.raiseEvent(scene);
+    assert.ok(Math.abs(camera.frustum.fovy - 0.5) < 1e-12, `aspect ${aspect}`);
+  }
+  camera.switchToOrthographicFrustum();
+  assert.doesNotThrow(() => port.setFov({ vertical: 0.4 }));
+  assert.throws(() => port.setFov({ vertical: Math.PI }), RangeError);
+  assert.throws(() => port.setFov({ vertical: NaN }), RangeError);
+});
diff --git a/src/render/cesium/harness.js b/src/render/cesium/harness.js
index 184343c7a..15bf22588 100644
--- a/src/render/cesium/harness.js
+++ b/src/render/cesium/harness.js
@@ -27,6 +27,8 @@ export const CESIUM_CHECKS = new Set([
   'camera.trace.flyTo with a duration of 0 completes inside the call',
   'camera.trace.flyTo where the camera already is completes inside the call',
   'camera.viewRectangle',
+  'camera.fov',
+  'camera.trace.view and projection matrices',
   'draw.drillPick',
   'draw.ids',
   'draw.models',