ChimpStackr

ChimpStackr is a free, open-source application for focus stacking, available with a graphical interface and a headless command-line tool. It provides Laplacian Pyramid, Weighted Average, Depth Map, and Exposure Fusion methods. Automatic alignment can handle translation, Euclidean rotation, similarity rotation and scale, and affine correction. A 16-bit processing pipeline preserves bit depth from RAW input through output, and auto-crop removes black edges created by alignment shifts. Users can add image files or folders by dragging them into the app, compare inputs and results with a slider, and pause, resume, or cancel long-running stacks. The project lists Windows ZIP, macOS DMG, and Linux x86-64 AppImage downloads. RAW files are supported, and TIFF and PNG are listed output formats. The project describes HDR exposure fusion as useful for varying exposure or lighting, but not as a focus-stacking method. Building from source requires Python 3.9–3.13, and builds can be made only for the current platform. ChimpStackr is licensed under GPL-3.0.

ChimpStackr provides alignment, stacking, and comparison controls in both a GUI and command-line interface. Users should note the distinction between its focus-stacking methods and HDR exposure fusion.

ChimpStackr suits photographers or image-processing users who need a focus-stacking tool on Linux, macOS, or Windows. Its graphical and command-line interfaces offer different ways to run stacks.

ChimpStackr is free, open-source software for combining photographs made at different focus distances. It suits photographers who want detailed desktop controls or a scriptable command-line workflow across Windows, macOS, and Linux. Its RAW-aware, 16-bit processing and flexible alignment are compelling, provided you do not mistake its exposure-fusion option for a focus-stacking method.

Overview

ChimpStackr offers Laplacian Pyramid, Weighted Average, and Depth Map methods for focus stacking, alongside Exposure Fusion (HDR). The first three address the usual task of extending depth of field across a sequence of focus distances. Exposure Fusion serves a different job: the project positions it for frames with varying exposure or lighting, not for focus stacking. That distinction matters when choosing a method, especially if you expect every algorithm in one menu to solve the same problem.

Automatic alignment can correct simple translation, Euclidean rotation, similarity rotation and scale, or affine changes. In practice, that range covers everything from a shifted camera to frames with rotation, resizing, or more complex perspective-related movement. Auto-crop then removes the black borders alignment can leave around the composite, while auto-tuning derives parameters from image resolution so users have less routine calibration to perform.

Key features

The 16-bit pipeline keeps bit depth from RAW input through the exported image. Photographers preserving subtle tonal gradations therefore avoid an avoidable precision reduction during stacking. ChimpStackr writes TIFF and PNG files, giving a choice between a production-oriented image format and a broadly supported raster format.

The graphical interface accepts image files or folders by drag and drop and provides a slider for comparing input and output. Long stacks can be paused, resumed, or cancelled, useful when a large sequence would otherwise tie up the application. A headless command-line tool covers terminal-driven and repeatable workflows, making the software more suitable for automation than a GUI-only stacker.

Downloads include a Windows ZIP, macOS DMG, and Linux x86-64 AppImage. Anyone compiling from source needs Python 3.9 through 3.13, and a build can target only the platform on which it is made. The project is GPL-3.0 licensed. Its README mentions gallery work post-processed in darktable, but does not describe a direct integration, so darktable remains a separate part of the workflow.

Pricing

ChimpStackr has one plan: ChimpStackr costs free. It is a multi-platform focus-stacking application under GPL-3.0, with no paid tier or free trial. That makes it the straightforward choice for photographers who need the full published feature set without a subscription. There are no stated seat quotas, usage allowances, renewal charges, or time limits; users who prefer commercial support or a formal service commitment should look elsewhere.

Platforms

Native releases cover Linux, macOS, and Windows. The Windows ZIP, macOS DMG, and Linux x86-64 AppImage are the practical installation paths. Source builders must use Python 3.9–3.13 and can produce a build only for their current platform. RAW files are supported, with TIFF and PNG as output formats.

Who it's for

ChimpStackr is a strong fit for photographers assembling close-up, macro, product, or other focus-bracketed sequences who want to retain RAW bit depth and choose among several stacking approaches. It also suits technically inclined users who need a headless command-line process alongside a visual editor, or who value GPL-3.0 software that runs on all three major desktop operating systems.

It is less suitable if your primary requirement is HDR exposure blending rather than focus stacking, since Exposure Fusion is explicitly described for changing exposure or lighting. Users expecting a built-in darktable connection, certified security controls, compliance documentation, or a stated support policy will not find those commitments in the project description.

Pros and cons

Pros

• Preserves 16-bit RAW data: keeps higher-precision tonal information through output.
• Broad alignment control: translation, rotation, scale, and affine correction address varied frame movement.
• GUI and headless CLI: supports both interactive editing and terminal-based workflows.
• Useful run control: pause, resume, and cancel actions are valuable for long stacks.
• Free and GPL-3.0: removes licensing cost across Linux, macOS, and Windows.

Cons

• Method naming can mislead: Exposure Fusion is for varying exposure or lighting, not focus stacking.
• No stated support or compliance program: organizations needing formal assurances must provide them separately.
• Source builds are platform-bound: compiling does not produce cross-platform packages from one environment.

Alternatives

Focus Stacking Online is the better pick when browser access or mobile support matters; it is free and runs on Android, iOS, Linux, macOS, the web, and Windows.

ImageFocus Alpha suits owners of compatible Euromex camera models who want free software tailored to that hardware.

CKAN is another free, open-source option under the MIT license for users who prefer that licensing model, with Linux, macOS, and Windows support.

CombineZP is a Windows-only, GPL-licensed alternative with a compiled x86 version referenced.

focus-stack is worth considering for users seeking free software across Linux, macOS, and Windows without stated pricing or usage limits.

Open Galileo is a Windows option the maker says will always be free, with voluntary donations and no stated restrictions.

Aduku Stacker targets macOS 13 and later and Windows users wanting a separate desktop stacker.

FocusFusion is a Windows freemium alternative for readers who prefer that distribution model.

Verdict

Choose ChimpStackr if you want free, cross-platform focus stacking with RAW support, 16-bit preservation, adjustable alignment, and both GUI and command-line control. Its main reason to look elsewhere is equally clear: exposure-fusion users, organizations needing documented support or compliance, and photographers tied to specialized hardware or browser workflows may be better served by another tool.