ImageReasonFocus, Depth of Field, and Macro
How many focus-stack frames do I need?
Enter your subject depth and a tested usable focus slice to get a frame count, step distance, overlap margin, and capture checklist.
Answer
Want to learn more? Circle of Confusion and Depth of Field
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Calculate to see the depth ruler.
| Overlap | Frames |
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Calculate a result to generate a copyable plan.
A focus stack is a coverage plan
A focus stack is a coverage plan. The subject has a depth from its nearest important detail to its farthest important detail, and each capture contributes a usable slice of that depth. The key word is usable. A theoretical depth-of-field number is not automatically the portion of a frame you would accept at the intended output. Field curvature, magnification, focus precision, movement, stacking alignment, and the way the image will be viewed can all reduce the practical slice.
This planner asks you to enter a tested usable slice depth. Make one frame at the planned magnification, aperture, light, and output assumption, then decide how much object depth it covers with acceptable margin. Enter the total depth you need to cover and the overlap you want between slices. The planner calculates the capture step, frame count, a small coverage margin created by rounding up, and optional storage.
For example, a 20 mm subject depth with a 2 mm usable slice and 30% overlap uses a 1.4 mm step. With 10% padding, the plan covers 22 mm in 16 frames. A lower overlap reduces frames but leaves less tolerance if focus movement is imperfect. A higher overlap adds capture and processing time. Neither setting is universally better because the subject, setup stability, and intended output decide how much margin is useful.
Use the ruler view to see where the stack begins and ends. Start before the nearest critical feature, keep exposure and lighting consistent, and do not change magnification or camera position mid-stack unless your method accounts for it. Test early frames for motion, reflections, and alignment.
FAQ
- Why not calculate the step directly from my lens?
- A practical stacking step depends on output criterion, magnification, field curvature, focus precision, and setup behavior. A test-derived usable slice is more honest.
- Does more overlap always make a better stack?
- More overlap adds tolerance but also adds frames, time, storage, and motion risk. Test the setup.
- Can this control my focus rail?
- No. It provides a capture plan and does not connect to camera or rail hardware.