Is exposure fusion different from HDR, or just another name for it?

Exposure fusion and HDR are closely related, but they are not exactly the same thing.

Traditional HDR workflow usually means: combine multiple exposures into a high-dynamic-range image, then tone-map that HDR data back into a viewable image. Exposure fusion takes a different approach: it blends the original exposures directly, typically weighting pixels by things like exposure, contrast, and saturation, without necessarily creating an HDR file or doing tone mapping.

So, exposure fusion is best understood as a different method for solving the same problem: capturing and displaying a scene with more dynamic range than a single exposure can handle.

Whether you call it “HDR” depends on how broadly you define HDR. In a broad historical sense, yes, it falls under HDR imaging. In the narrower modern digital sense, many people treat exposure fusion as distinct from true HDR generation and tone mapping.

For tagging, it makes sense to group it under hdr, but exposure fusion can also be useful as a more specific subtopic.