HDRMerge

Overview

HDRMerge combines exposure-bracketed raw files, or bracketed frames within one raw file, into a DNG 1.4 image with floating-point data. It uses less noisy input pixels to preserve shadow detail. The result is intended for further development in software that supports high-dynamic-range raw DNGs, not for completing the HDR image inside HDRMerge.

That division of work is useful for photographers who want to bring an HDR merge into a familiar raw workflow. It is a poor fit for someone seeking an all-in-one HDR editor or a tool that can reconcile mismatched source images.

Key features

Ghost correction and batch processing

The graphical interface lets users edit the merge mask to address ghosts caused by objects moving between exposures. This gives some control over motion artifacts, but requires manual correction when the initial merge leaves visible ghosts. For repeated image sets, the command-line interface supports batch processing and avoids handling each set individually through the graphical interface.

Alignment and compatibility

HDRMerge can align small translations and crop the output to the area shared by the source images. Those adjustments help when bracketed frames shift slightly, but do not remove the need for compatible inputs: size, orientation, Bayer pattern, and black and white levels must match. The manual says this usually means using images made with the same camera, so HDRMerge is not a flexible choice for combining files from different cameras or settings.

Raw workflow and support

RawTherapee, darktable, and recent Adobe products support the floating-point DNG formats HDRMerge produces. The maker’s intended workflow is to merge first and tone-map later in another program that supports high-dynamic-range raw DNG images. That keeps HDRMerge focused, but adds a separate step and requires compatible development software.

For bug reports and feature requests, the maker directs users to GitHub and asks for the HDRMerge version, full error messages, and a link to sample raw files. That is a practical route for technical issues, though users should be prepared to provide diagnostic material.

Pricing

HDRMerge is free software under the GNU General Public License, version 3 or later. Its Free plan costs 0.00 USD per free and includes both HDR merge modes, RAW file support, DNG 1.4 output, and Windows, macOS, and Linux support. There is no free-trial distinction to weigh against a paid tier: the software itself is free, with no other plan described.

Platforms

HDRMerge runs on Windows, macOS, and Linux. Its desktop focus suits photographers working with raw files on those systems; no web or mobile platform is part of the stated offering.

Who it's for

Choose HDRMerge if you work with compatible bracketed raw images, want a floating-point DNG that retains shadow information, and already have a suitable program for later tone mapping. Its batch-capable command line also makes it a sensible option for processing multiple raw sets. Look elsewhere if your inputs do not meet the matching requirements or you want a single application to merge and finish an HDR image.

Pros and cons

Pros

• Free and open-source: The GPL-3.0-or-later license makes it usable without a paid plan.
• Shadow-preserving output: Floating-point DNG 1.4 output uses less noisy source pixels to preserve shadow detail.
• Useful correction and throughput options: Mask editing addresses ghosts from moving objects, while the command-line interface supports batch processing.
• Fits established raw development: RawTherapee, darktable, and recent Adobe products support its output format.

Cons

• Strict input matching: Source images must match in several technical properties, usually requiring the same camera.
• Not a complete HDR editor: Tone mapping happens later in another compatible program.
• Motion cleanup may take effort: Ghost correction relies on editing the merge mask in the graphical interface.

Alternatives

HDR Software is a useful starting point if you want to compare HDR tools across the category.

• Luminance HDR is another free, open-source desktop option for Windows, macOS, and Linux; choose it if you want HDR imaging software rather than HDRMerge’s raw-merge-to-DNG workflow.
• PhotomatixCL is a paid, cross-platform alternative with a free plan and trial; consider it if you want to compare a credit-based paid offering with HDRMerge’s free GPL software.
• SNS-HDR is a freemium option for macOS and Windows with a free trial; consider it if those are your platforms and you prefer a freemium alternative.
• ColorForge is a free option spanning web, desktop, and mobile platforms; choose it if platform breadth matters more than HDRMerge’s raw-merge workflow.
• easyHDR is a paid option with a free plan and trial; consider it if you want to compare its home or commercial licensing approach with HDRMerge’s free software.
• HDR Merge Master is another free desktop alternative for Windows, macOS, and Linux.
• Tembrica Video Background Remover is a web-based alternative in the directory.
• Instant Meshes is a free desktop alternative for Windows, macOS, and Linux.

Verdict

HDRMerge is the right choice for photographers who want a free, batch-capable way to combine compatible raw exposures into a shadow-preserving DNG for later development. Its main reason to choose it is that focused raw workflow without a purchase price; its main reason to look elsewhere is the combination of strict input matching and a separate tone-mapping step.