What is focus stacking?

Focus stacking combines multiple images shot at different focus distances to create a single image with extended depth of field. Each frame is sharp in a different zone. Software (Photoshop, Helicon Focus, Zerene Stacker) blends the sharp regions from each frame.

How many frames do I need?

It depends on the total depth to cover and the DOF per frame. Macro at 1:1 might need 20-50 frames for a few centimetres. Landscape focus stacking might need 3-5 frames from foreground to infinity. Always shoot a few extra frames for safety overlap.

What aperture should I use for stacking?

Use f/5.6 to f/11 for the sharpest per-frame results. Avoid very small apertures (f/16+) where diffraction reduces sharpness. With stacking, you do not need small apertures for depth — you get depth from multiple frames. Wider apertures give sharper individual frames.

How do I shoot a focus stack?

Use a tripod. Manual focus mode. Start at the nearest point and shift focus slightly for each frame. Many cameras have built-in focus stacking (focus bracketing). Alternatively, use a macro rail for precise mechanical focus steps. Keep aperture and exposure constant.

PhotoCalcs

Focus Stacking Calculator — Number of Frames

Plan focus stacking steps for macro or landscape shots with correct overlap.

Focal Length

Actual focal length printed on the lens, in millimetres (e.g. 100mm macro).

Aperture

Working f-stop for the stack. f/5.6–f/11 give sharp frames; smaller apertures lose detail to diffraction.

Near Distance

Distance to the nearest point that must be sharp (closest part of the subject).

Far Distance

Distance to the farthest point that must be sharp (back of the subject).

Sensor (CoC)Sensor format sets the circle of confusion (CoC) used to size each frame's depth of field. Full-frame ≈ 0.029mm; APS-C ≈ 0.018–0.019mm; Micro Four Thirds ≈ 0.015mm.

How We Calculate This

DOF per Frame

Depth of field per frame is found from the standard thin-lens equations at the average focus distance: hyperfocal H = f² ÷ (N × c) + f, near limit Dn = H·s ÷ (H + (s − f)) and far limit Df = H·s ÷ (H − (s − f)), where f is focal length (mm), N the f-number, c the circle of confusion (mm) and s the focus distance. DOF per frame = Df − Dn.

Number of Frames

Frames = ⌈total depth ÷ (DOF × 0.7)⌉ + 1

The 0.7 factor leaves 30% overlap between frames for reliable blending. The focus step is then the total depth spread evenly across the frames.

Macro accuracy note

These thin-lens equations are intended for general and landscape distances. At true macro magnifications (greater than roughly 1:4) depth of field is better estimated from the magnification-based formula DOF = 2·N·c·(m + 1) ÷ m², so for 1:1 work add extra frames or use a dedicated macro DOF table (e.g. Zerene Stacker or Points in Focus).

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard optical and photographic formulas. Results may vary with specific equipment.