diff --git a/web/MediaField.tsx b/web/MediaField.tsx
index 901fa37..5739ee3 100644
--- a/web/MediaField.tsx
+++ b/web/MediaField.tsx
@@ -187,12 +187,22 @@ export const MediaField = ({
     to. That is also the behaviour somebody expects from a `+`: the middle of what I am looking at
     stays where it is.
   */
-  const zoomBy = (factor: number) => {
+  const zoomBy = (step: number) => {
     if (!current || !natural || !onCropChange) return;
 
     const base = centredCrop(natural.w / natural.h, slotAspect);
-    // Fit is the floor — there is no more picture — and 8x is where a rendition runs out of pixels.
-    const zoom = Math.min(8, Math.max(1, (base.w / current.w) * factor));
+    /*
+      A tenth per press, ADDED rather than multiplied.
+
+      A factor compounds: the same button is a 0.25x step at fit and a 1.75x step at 7x, so the first
+      press does almost nothing and the last one throws the picture across the frame. A fixed step is
+      the same amount of change every time, which is what somebody nudging a crop into place is asking
+      for — and it makes the number beside the buttons predictable, which a factor never is.
+
+      Fit is the floor — there is no more picture — and 8x is where a rendition runs out of pixels.
+      Rounded, because floating point turns 1 + 0.1 + 0.1 into 1.2000000000000002 and the label shows it.
+    */
+    const zoom = Math.round(Math.min(8, Math.max(1, (base.w / current.w) + step)) * 10) / 10;
 
     const w = base.w / zoom;
     const h = base.h / zoom;
@@ -348,7 +358,7 @@ export const MediaField = ({
                   size="sm"
                   variant="ghost"
                   className="size-6 p-0"
-                  onClick={() => zoomBy(1 / 1.25)}
+                  onClick={() => zoomBy(-0.1)}
                   disabled={zoomLevel <= 1.001}
                   title="Zoom out"
                 >
@@ -363,7 +373,7 @@ export const MediaField = ({
                   size="sm"
                   variant="ghost"
                   className="size-6 p-0"
-                  onClick={() => zoomBy(1.25)}
+                  onClick={() => zoomBy(0.1)}
                   disabled={zoomLevel >= 7.99}
                   title="Zoom in"
                 >