Crop and Straighten

The Crop button in the Develop view header opens a dedicated crop and straighten editor. It replaces the center canvas while active, and gives you handles, a rule-of-thirds grid, an aspect-ratio dropdown, and a straightening slider.

When to crop

The most common reasons to crop a stacked macro image:

Trim alignment edges. Stacking aligns frames by warping them into a common coordinate space. The edges often have a small black or transparent border from this warping. A crop reclaims a clean rectangle.
Improve composition. Tighten in on the subject, remove distracting edge elements, recompose to a different aspect.
Match output dimensions. Crop to 4:3 for a print, 1:1 for Instagram, 16:9 for a web header.

Cropping is non-destructive — you can re-open the crop editor and adjust at any time. The original full-resolution pixels are always preserved.

The crop rectangle

When you open the crop editor, you’ll see:

The image, fitted to the available space with letterbox padding around it.
A crop rectangle covering the full image by default (or your previous crop, if you’ve cropped before).
8 draggable handles — 4 corners and 4 mid-edge handles.
A rule-of-thirds grid overlaid on the rectangle (visual guide; doesn’t snap).
The area outside the crop rectangle is dimmed so you can see what’ll be trimmed away.

Resizing the crop

Drag a corner handle — resize freely from that corner.
Drag a mid-edge handle — resize from that edge only.
Drag inside the crop rectangle — move the whole crop without changing its size.

If an aspect ratio is locked (see below), corner handles maintain the ratio; mid-edge handles still resize freely along their axis but the opposite axis follows.

Aspect ratio

The Aspect dropdown in the toolbar offers:

Free — drag handles independently.
1:1 — square (Instagram, profile pictures).
3:2 — standard DSLR/mirrorless sensor ratio.
4:3 — Micro Four Thirds, many compact cameras, print-friendly.
16:9 — widescreen, web headers.
3:4 — portrait orientation of 4:3.
9:16 — portrait orientation of 16:9 (Instagram Stories, TikTok).

Changing the aspect locks the crop rectangle to that ratio immediately, snapping the current crop to fit. Choose Free again to release the lock.

Straighten

The Straighten slider rotates the image by ±90°. The crop rectangle rotates with it (the image is what rotates inside the rectangle, not the rectangle), so the visible result is a rotated, cropped image.

The current rotation reads out as ±0.0° next to the slider.

Zoom and pan inside the crop editor

The crop editor has its own zoom/pan controls separate from the main Develop view:

Scroll — zoom in/out (1.04× per scroll click — fine-grained).
+ / = keys — zoom in by 1.25×.
- key — zoom out by 1.25×.
Middle-click drag or left-click drag outside the crop rect — pan when zoomed in.
The cursor switches to a closed hand while panning.

Zoom is useful for precision crops near important edges — like cropping right up against an antenna or wing without clipping it.

Apply, Reset, Cancel

The toolbar at the bottom of the crop editor has three actions:

Reset — restore the crop to the full image (no crop). Doesn’t apply or cancel; just returns the rectangle to its default position.
Cancel — discard any changes you made in this session and return to Develop view with the previous crop intact.
Apply — commit the crop. The crop becomes part of the result; the Develop view shows the cropped image; the history strip thumbnail updates.

If you click outside the editor by mistake, the crop stays open — nothing commits until you click Apply.

Re-cropping later

The crop is non-destructive. To change the crop, click Crop again from the header toolbar — you’ll re-enter the editor with the current crop selected, ready to adjust. To remove the crop entirely, hit Reset then Apply in the editor.

Tips

Straighten before fine-cropping. A 1° rotation changes the visible edges by a few pixels — straighten first so your final crop is tight.
Output dimensions follow the crop. If you crop a 6000×4000 image to 50% area, your saved TIFF/JPEG/DNG is half the linear dimensions. Crop with your output destination in mind.