HDR merge

HDR merge

Merge a bracket of exposures into one natural picture with detail in the shadows and the sky: aligned, deghosted and blended in your browser. Free; nothing uploaded.

HDR merge

Your bracket, one picture

Exposures are read and merged in this browser tab. Nothing is uploaded.

      Save as

      JPG and TIFF keep the camera data of the middle exposure, never its location.

      What the merge does

      It sorts the exposures by brightness and takes the middle one as the reference. It aligns the others to it on copies equalised so that frames stops apart look alike, and replaces anything that moved with the reference carried to that frame's exposure. Then it blends every pixel from the frames where that part of the scene is best exposed, sharpest and most colourful, through deep image pyramids so that broad tones join without bands. This is exposure fusion (Mertens, Kautz and Van Reeth, 2007): the result needs no tone mapping, and skies stay skies.

      Shooting a bracket that merges

      • Aperture priority, so the depth of field stays the same and only the shutter speed changes.
      • Three frames at −2, 0 and +2 EV for a bright sky and a dark foreground; five at one-stop steps for gentler light.
      • Continuous drive, so the frames follow each other within a second; handheld is fine.
      • Focus and white balance fixed for the whole bracket.

      Where your camera keeps auto exposure bracketing, and how many frames to take: the exposure-bracketing guide.

      What it does not do (yet)

      • No RAW merge into a floating-point HDR file: the output is a finished picture (JPG, PNG or 16-bit TIFF).
      • Alignment is a shift and a slight rotation: a bracket shot while walking will not line up.
      • One camera at one size: exposures of different sizes are refused by name.

      Focus bracketing is the other bracket: the focus stacker merges frames focused at different distances, and the panorama stitcher joins frames turned side by side.

      HDR merge: questions

      Is the HDR merge free, and are my photos uploaded?

      It is free, with no account and no watermark, and the photos never leave your computer: they are aligned and merged inside this browser tab.

      How many exposures do I need, and how far apart?

      Three exposures two stops apart (-2, 0, +2 EV) cover most scenes with a bright sky; five at one-stop steps give smoother tones; a sunset into the sun may want seven. Shoot them in aperture priority so only the shutter speed changes.

      Can I shoot the bracket handheld?

      Yes. Use continuous drive so the frames follow each other quickly; the merge aligns them before blending. A tripod is still better for long exposures in low light.

      What happens to people or cars that moved between the frames?

      With “Remove ghosts” on, anything that moved is taken from the middle exposure only, so it appears once and solid instead of as see-through copies.

      Is this tone mapping?

      No tone-mapping step is needed: the merge is exposure fusion, which blends the best-exposed parts of every frame straight into a displayable picture, so it looks natural rather than “HDR-ish”. Save the 16-bit TIFF if you want to keep editing.

      Can I merge RAW files?

      Not here yet. Convert the bracket with the RAW to JPG converter on this site first (keep “Develop the RAW” and the same brightness for every frame), then merge the results.