diff --git a/docker/frontend/src/Library.tsx b/docker/frontend/src/Library.tsx
index 3f007ad..53f15c9 100644
--- a/docker/frontend/src/Library.tsx
+++ b/docker/frontend/src/Library.tsx
@@ -110,6 +110,7 @@ const OPEN_KEY = 'recipescam.library.open';
 // shut them out, and the chip wrote that first answer down on the very first
 // visit — so the old key holds 'true' for every reader who never touched it, and
 // reading it would keep them on a default they never chose.
+const DEEP_KEY = 'recipescam.library.deep2';
 const VIEW_KEY = 'recipescam.library.view';
 const SORT_BY_KEY = 'recipescam.library.sortBy';
 const SORT_DIR_KEY = 'recipescam.library.sortDir';
@@ -460,6 +461,13 @@ function Catalogue({ admin, user }: { admin: boolean; user: User | null }) {
     for (const parent of nodeParents) set.add(parent);
     return set;
   });
+  // Whether the strip draws the whole branch under the open node or only the
+  // node itself. On to begin with: a folder is its branch, so the root draws the
+  // frames of every folder under it — a server's own folder among them — and a
+  // frame two levels down is not a frame the reader has to go and find. The
+  // toggle keeps the last word, and the answer is picked up where the last visit
+  // left it, the same as the open node below.
+  const [deep, setDeep] = useState(() => recall(DEEP_KEY) !== 'false');
   // The frame that is up in the open node — raised by a click on its thumbnail,
   // and picked up where the last visit left it, so a reader who leaves for the
   // studio comes back to the negative they were looking at rather than to the
@@ -959,6 +967,9 @@ function Catalogue({ admin, user }: { admin: boolean; user: User | null }) {
   useEffect(() => {
     keep(OPEN_KEY, [...expanded].join(','));
   }, [expanded]);
+  useEffect(() => {
+    keep(DEEP_KEY, String(deep));
+  }, [deep]);
   useEffect(() => {
     keep(VIEW_KEY, view);
   }, [view]);
@@ -1533,7 +1544,10 @@ function Catalogue({ admin, user }: { admin: boolean; user: User | null }) {
   // folder — that one is not a folder of this roll.
   const relOf = useCallback(
     (key: string): string | null => {
-      if (!rootName) return null;
+      // `null` and not falsy: a picked drive root is named `\`, which folds to the
+      // empty root, and a guard on the name itself would take every row of such a
+      // roll for a row of another folder.
+      if (rootName === null) return null;
       const normRoot = normPath(rootName);
       const normKey = normPath(key);
       if (normKey === normRoot) return '';
@@ -1602,9 +1616,9 @@ function Catalogue({ admin, user }: { admin: boolean; user: User | null }) {
     // not set the job off again; the rows of that same render are what goes.
     const normRoot = normPath(rootFolder.name);
     const rows = photos.filter((p) => normPath(p.folder ?? '') === normRoot);
-    void makeThumbsFor(rootFolder, rel, { below: true, rows });
+    void makeThumbsFor(rootFolder, rel, { below: deep, rows });
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [loaded, makeThumbsFor, node, photos.length, relOf, rootFolder]);
+  }, [deep, loaded, makeThumbsFor, node, photos.length, relOf, rootFolder]);
 
   // The tree: one row per picked folder, then one per subfolder, indented by its
   // depth — the folders the walk has named, whether or not a frame has been read
@@ -1805,28 +1819,36 @@ function Catalogue({ admin, user }: { admin: boolean; user: User | null }) {
     setNode(nodes.find((n) => n.key === rootName || n.key === normPath(rootName ?? ''))?.key ?? nodes[0]?.key ?? null);
   }, [loaded, node, nodes, rootName]);
 
-  // What the open node draws: its own frames and those of every folder under it,
-  // which is the whole of the branch the row above it counted.
+  // What the open node draws: its own frames and, while the toggle is on, the
+  // ones in every folder under it — the whole of the branch the row above it
+  // counted, a server's own folder among them.
   const shown = useMemo(() => {
-    if (!rootName) return photos;
+    // The empty root is a root: `D:\` is what the picker calls a drive, and `''`
+    // is what it folds to. Read as "no folder picked" it hands back the whole
+    // catalogue for every row of that roll — the root's frames under a year, and
+    // a server's frames under both.
+    if (rootName === null) return photos;
     const normRoot = normPath(rootName);
     const normNode = normPath(node ?? '');
     const dir = normNode === normRoot ? '' : normNode.slice(normRoot.length + 1);
     const below = dir === ''
       ? (p: LibraryPhoto) => normPath(p.dir ?? '') !== ''
       : (p: LibraryPhoto) => normPath(p.dir ?? '').startsWith(`${dir}/`);
+    const own: LibraryPhoto[] = [];
     const both: LibraryPhoto[] = [];
     for (const p of photos) {
       if (normPath(p.folder ?? '') !== normRoot) continue;
       const pDir = normPath(p.dir ?? '');
-      if (pDir === dir || below(p)) both.push(p);
+      const isOwn = pDir === dir;
+      if (isOwn) own.push(p);
+      if (isOwn || below(p)) both.push(p);
     }
-    // A folder is its branch: the row counts what sits at or under the folder, so
-    // the wall under it holds the same frames, and a frame two levels down is not
-    // a frame the reader has to go and find. A sibling's frames are the one thing
-    // left out.
-    return both;
-  }, [node, photos, rootName]);
+    // A row counts what sits at or under its folder, so a folder with nothing of
+    // its own to draw is drawn as its branch whatever the toggle says: a folder
+    // whose frames all lie one level down would otherwise open on an empty screen
+    // under a number that says otherwise.
+    return deep || !own.length ? both : own;
+  }, [deep, node, photos, rootName]);
 
   // What the thumbnail view draws, out of what the open node holds. A frame's
   // hour is the hour the shutter fired in, on this machine's clock — the same
@@ -1919,7 +1941,7 @@ function Catalogue({ admin, user }: { admin: boolean; user: User | null }) {
     // ponytail: only the year option list is folder-derived; stars and hours are
     // fixed lists that cannot go stale. Re-check the others if they ever grow.
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [node, rootName, years]);
+  }, [node, deep, rootName, years]);
 
   // On-demand fetch for selected year if user has Immich servers and local photos for that year are missing
   const fetchYearPhotos = useCallback(
@@ -2908,6 +2930,19 @@ function Catalogue({ admin, user }: { admin: boolean; user: User | null }) {
                       <rect x="9" y="9" width="5" height="5" rx="1" />
                     </svg>
                   </button>
+                  {/* Whether the strip draws the branch under the open folder or
+                      only the folder itself. The label says what the click does,
+                      `on` says where the strip is now. */}
+                  <button
+                    type="button"
+                    className={`chip${deep ? ' on' : ''}`}
+                    data-key="lib-subs"
+                    aria-pressed={deep}
+                    title={t('lib.subsHint')}
+                    onClick={() => setDeep((prev) => !prev)}
+                  >
+                    <span className="chip-label">{t(deep ? 'lib.subsHide' : 'lib.subsShow')}</span>
+                  </button>
                 </>
               ) : null}
             </div>
diff --git a/docker/frontend/src/i18n/en.ts b/docker/frontend/src/i18n/en.ts
index 50daa1e..3176faa 100644
--- a/docker/frontend/src/i18n/en.ts
+++ b/docker/frontend/src/i18n/en.ts
@@ -282,6 +282,9 @@ export const en: Dict = {
   'lib.rail': 'Timeline',
   'lib.prev': 'Previous frame',
   'lib.next': 'Next frame',
+  'lib.subsShow': 'SHOW SUBFOLDERS',
+  'lib.subsHide': 'THIS FOLDER ONLY',
+  'lib.subsHint': 'Frames in subfolders: the whole branch under the open folder, or only what that folder holds itself.',
   'lib.open': 'Open in the studio',
   'lib.openExplorer': 'Open in window explorer',
   'lib.openLocation': 'Open at location',
diff --git a/docker/frontend/src/i18n/vi.ts b/docker/frontend/src/i18n/vi.ts
index 052946c..ae9117c 100644
--- a/docker/frontend/src/i18n/vi.ts
+++ b/docker/frontend/src/i18n/vi.ts
@@ -293,6 +293,10 @@ export const vi = {
   'lib.rail': 'Dòng thời gian',
   'lib.prev': 'Ảnh trước',
   'lib.next': 'Ảnh sau',
+  'lib.subsShow': 'HIỆN CẢ THƯ MỤC CON',
+  'lib.subsHide': 'CHỈ THƯ MỤC ĐANG CHỌN',
+  'lib.subsHint':
+    'Ảnh trong thư mục con: hiện cả nhánh dưới thư mục đang chọn, hoặc chỉ ảnh của chính thư mục đó.',
   'lib.open': 'Mở trong studio',
   'lib.openExplorer': 'Open in window explorer',
   'lib.openLocation': 'Open at location',
diff --git a/docker/frontend/src/styles/app.css b/docker/frontend/src/styles/app.css
index 1041599..945caad 100644
--- a/docker/frontend/src/styles/app.css
+++ b/docker/frontend/src/styles/app.css
@@ -1555,15 +1555,15 @@ form[data-key='immich-modal'] {
    read by the year first and the month under it after. */
 .lib-ruler-band { position: absolute; left: 0; right: 0; background: var(--bg-elev); border-radius: 3px; }
 .lib-ruler-tick { position: absolute; left: 0; width: 10px; height: 1px; background: color-mix(in srgb, var(--text-dim) 30%, transparent); }
-/* A year is the ruler's own rule: a hairline across the column with the year in
-   brackets at the end of it — `-----[2024]`, which is what a ruler reads like.
-   The line is the months' own grey, since a year is a tick like any other and not
-   a band; the brackets are drawn here so the tick still reads as its bare year. */
+/* A year is the ruler's own rule: `-----2024`, a run of rule across the column
+   with the bare year at the end of it, which is what a ruler's own edge reads
+   like. The run is the page's ruler ink at its heavy weight — the ink the ticks
+   are drawn in, one weight up, so a year separates where a month only marks — and
+   not the solid `--text-dim` it first was, which stood out of the column like a
+   border. */
 .lib-ruler-tick.lib-ruler-year { left: 0; right: 0; width: auto; height: 1px; background: none; display: flex; align-items: center; gap: 4px; }
-.lib-ruler-tick.lib-ruler-year::before { content: ''; flex: 1 1 auto; height: 1px; background: color-mix(in srgb, var(--text-dim) 30%, transparent); }
+.lib-ruler-tick.lib-ruler-year::before { content: ''; flex: 1 1 auto; height: 1px; background: var(--tick-strong); }
 .lib-ruler-tick.lib-ruler-year i { position: static; font-size: 9px; font-style: normal; font-weight: 700; letter-spacing: 0.02em; color: var(--text-dim); }
-.lib-ruler-tick.lib-ruler-year i::before { content: '['; }
-.lib-ruler-tick.lib-ruler-year i::after { content: ']'; }
 .lib-ruler-tick.lib-ruler-year.on { width: auto; background: none; }
 .lib-ruler-tick.lib-ruler-year.on::before { background: var(--accent); }
 .lib-ruler-tick.lib-ruler-year.on i { color: var(--accent); }