Stacking

Once you’ve selected frames in the filmstrip, pressing S (or clicking Stack selected images [S] →) hands them off to the stacker. This page explains what’s happening and what comes out the other side.

What focus stacking does

Macro depth of field is shallow — often a millimeter or less at high magnification. A single frame can only have a thin slice of the subject in focus. Focus stacking combines multiple frames shot at different focus distances into one image where every region is sharp.

Macro Studio’s stack happens in three phases:

Alignment — corrects for focus breathing (the magnification change between frames), camera movement, and rotation. Each frame is warped into the same coordinate space as the others. This runs automatically on every stack.
Sharpness analysis — for each pixel, the stacker measures which frame has the sharpest signal at that location.
Blending — the sharpest detail from every frame is combined into the final image.

One engine, nothing to configure

Earlier versions of Macro Studio asked you to choose a stacking method (Pyramid or Depth Map) and tune detail and depth sliders. That’s gone. Macro Studio now uses a single unified stacking engine that combines the strengths of those older approaches automatically — more detail, cleaner backgrounds, and fewer artifacts on difficult stacks, with nothing to pick or tune.

That means stacking is genuinely one click: select your frames and press Stack. The engine renders fine structures like antennae, hair, and bristles cleanly, keeps out-of-focus backgrounds smooth, and handles subjects whose parts cross over each other — without a method choice or a detail slider in sight.

GPU acceleration

Stacking is GPU-accelerated, and there’s nothing to switch on — Macro Studio detects your hardware and uses it automatically.

Any GPU works. Whether you have a discrete graphics card or an integrated GPU built into your processor (such as Apple Silicon), Macro Studio can hand work off to it.
The right work goes to the right place. We benchmark each step of the pipeline to know which computations are best handed to the GPU and which run faster on the CPU, then split the work accordingly.
Discrete GPUs are preferred automatically. On a system with both a discrete card and an integrated GPU, Macro Studio auto-detects them and picks the discrete one for the best performance.
No compatible GPU? No problem. Stacking falls back to the CPU automatically — you get the same image, it just takes a little longer.

What stacking outputs

When you press Stack, the result appears in two places:

The history strip at the bottom of the Editor — every stack and edit lands here (up to 25 results; older ones drop off the front as new ones arrive).
The center canvas — your active result, ready for masking, adjustments, crop, spot correct, and Save.

Stacking doesn’t write any files to disk on its own — the result lives in Macro Studio’s in-memory project until you Save…. That’s by design: you can stack, edit, and pick the best version before committing to disk.

Stacking a whole folder at once

Got a folder with several brackets mixed together? Autostack splits it into separate focus-bracket sets by capture time and stacks each one automatically. See Autostack.