ChimpStackr

ChimpStackr is free, open-source focus-stacking software for photographers who want desktop controls as well as a command-line workflow. Its RAW support, 16-bit processing and multiple alignment options make it a capable fit for detailed stacks, though one of its four named methods is intended for exposure fusion rather than focus stacking.

Overview

ChimpStackr combines frames shot at different focus distances using Laplacian Pyramid, Weighted Average, Depth Map or Exposure Fusion methods. That choice lets users compare approaches to a stack; Exposure Fusion is the exception, described for images with varying exposure or lighting, not for focus stacking.

Automatic alignment handles translation, Euclidean rotation, similarity rotation and scale, and affine correction. These options address different kinds of frame shifts, while auto-crop removes black edges introduced by alignment. Auto-tuning detects parameters from image resolution, which can spare users some manual adjustment.

Key features

The 16-bit processing pipeline preserves bit depth from RAW input through output, a useful quality-preserving feature for photographers who want to retain tonal information. Export formats are TIFF and PNG.

The graphical app accepts dragged image files or folders, and users can compare input and output with a slider. Long-running stacks can be paused, resumed or cancelled. A headless command-line tool supports users who prefer a terminal-based workflow or need to run stacking without the GUI.

Pricing

ChimpStackr is free: its plan costs nothing and includes multi-platform focus-stacking software under the GPL-3.0 license. There is no paid tier or free trial. The free plan covers the software without a stated usage quota; the project does not describe seat limits.

Platforms

ChimpStackr supports Linux, macOS and Windows. Release downloads include a Windows ZIP, macOS DMG and Linux x86-64 AppImage. Building from source requires Python 3.9–3.13, and builds can only be made for the current platform, so a source build is not a route to producing packages for several systems at once.

Who it's for

Choose ChimpStackr if you want a free desktop focus-stacking tool with RAW input, 16-bit processing, several alignment modes and the option of GUI or CLI use. It is also a reasonable fit for users who want to pause or cancel a long stack rather than wait for it to finish uninterrupted.

It is less suitable if you need a documented software integration, a stated security or compliance assurance, or support commitments. The project gives no such claims, and the mention of gallery images post-processed in darktable is not an integration. Users seeking exposure fusion as a focus-stacking method should also look elsewhere.

Pros and cons

• Pros: RAW support and a 16-bit pipeline preserve bit depth through output, with TIFF and PNG export.
• Pros: Multiple alignment corrections, auto-crop and resolution-based auto-tuning address common stack-preparation work.
• Pros: GUI and headless CLI workflows, plus pause, resume and cancel controls, provide flexibility for different users and long jobs.
• Cons: Exposure Fusion is described for varying exposure or lighting, not focus stacking, despite appearing among the named methods.
• Cons: Source builds are limited to the current platform, and require Python 3.9–3.13.

Alternatives

Focus Stacking Software is the broader directory for comparing tools in this category.

• Focus Stacking Online is a free alternative spanning web, mobile and desktop platforms if you want online access as well as installed software.
• CKAN is another free, open-source option, under the MIT license and available for Linux, macOS and Windows.
• ImageFocus Alpha is free across desktop and mobile platforms, and is designed for compatible Euromex camera models.
• PlaneFuse is free for personal and commercial use, with no tiers, and supports API, web, self-hosted and desktop platforms.
• focus-stack is a free option for Linux, macOS and Windows.
• ForgePix is free software under the MIT license for Linux, macOS and Windows.
• OpenFocus is free and open source; it offers a GUI for Windows and macOS and a CLI for Windows, macOS and Linux.
• Shine Stacker is a free, open-source download for Windows, Mac OS and Linux under the LGPL-3.0 license.

Verdict

ChimpStackr is a strong free choice for photographers who want RAW-compatible, 16-bit focus stacking with alignment controls and both GUI and CLI access. Its limits are the exposure-fusion method's mismatch with focus stacking and the absence of stated support or security assurances; choose another tool if either matters to your workflow.