Batch HDR merge in Lightroom Classic: what works, what breaks
Lightroom Classic can merge brackets in batches. Most people do not know this, because Adobe never put it in a menu. This page shows you how to do it, and then shows you the four points where it stops working on a real property shoot.
Last checked August 2026, against Lightroom Classic on macOSLinked sources verified
The short answer
Select your bracket. Press Cmd+Shift+H (Mac) or Ctrl+Shift+H (Windows).
Lightroom merges it in the background with default settings and no dialog. This is called a headless merge.
Defaults used: Auto Align on, Auto Tone on, deghosting Low. You do not get to change them per merge.
Step by step
- Import the shoot into Lightroom Classic.
- Go to the Library module. Select all photos with
Cmd+A. - Go to Photo → Stacking → Auto-Stack by Capture Time.
- Drag the time threshold slider until the stack count matches your bracket count. If you shot 300 frames in sets of three, you want 100 stacks.
- Collapse the stacks.
- Select the first stack. Press
Cmd+Shift+H. - Press the right arrow key. Press
Cmd+Shift+Hagain. Repeat.
Each merge produces a DNG next to the source frames, with -HDR added to the file name.
Where it breaks
1. You cannot select all the stacks and merge once
This is the one that matters. Selecting every stack and pressing Cmd+Shift+H does not merge
every stack. This is a long-standing reported bug, not a setting you have missed.
So step 7 above is a loop. For a 100-bracket house, that is 100 keystroke pairs. It is faster than the dialog, but it is not a batch operation. It is manual work with a shorter keystroke.
If Adobe has fixed this since we last checked, tell us and we will correct this page.
2. Concurrency is limited
Lightroom handles roughly five merges at once. Push past that and it slows down. Users have reported crashes at seven or more. So you cannot simply queue everything and walk away — you queue a few, wait, queue a few more.
3. Auto-Stack by Capture Time is a guess
Auto-stack groups by time gap alone. It does not read exposure values. This causes two failure modes:
- You shot fast. You moved to the next tripod position within the gap threshold, so two brackets merge into one stack of six.
- You paused. You adjusted something mid-bracket, so one bracket splits across two stacks.
Both are silent. You find out when a merged file looks wrong, which is after the merge.
There is no room awareness at all. Lightroom has no concept that frames 1–15 were the kitchen. It sees a flat timeline.
4. Defaults are all you get
Headless merge always uses Auto Tone and Low deghosting. A bright window and a dark hallway in the same house get identical treatment. If a specific merge needs different deghosting, you have to redo that one through the full dialog.
About the Adobe feature requests
Two of these get quoted a lot, and they are often mixed up.
- "Ability to batch process Photo Merge (HDR and panorama)", opened 27 April 2015 for Lightroom Classic. 218 replies. Status: Released. Headless merge is the release. The thread continued for years because people did not consider it a real batch feature. Recent replies are people posting AutoHotkey scripts.
- "Batch process HDR merges", opened 4 September 2025. Status: Open for Voting. This one is about Lightroom cloud, not Classic — the person filing it says the feature already exists in Classic and asks for it in the cloud version too.
So: batch merge in Classic is not an unshipped feature. It shipped, in a limited form, and the limits are the four above.
What else you can use
| Tool | Auto-groups brackets | Real unattended batch | Cost | Best for |
|---|---|---|---|---|
| Lightroom Classic headless merge | Time-gap stacking only | No — one keystroke pair per stack | Included in your plan | Low volume, already in Lightroom |
| HDR Batch Plugin for Lightroom (HDRsoft) | Uses stacks | Yes, and applies a preset during merge | €59 | Staying inside Lightroom, high volume |
| Photomatix Pro 7 | Yes, by folder; detects varying bracket counts | Yes | €89 one-time, no subscription | Full tone-mapping control; Windows users |
| HDR Forge | Yes — exposure, timestamp and filename | Yes | $9.99 one-time (Mac App Store) | Cheapest way to solve merging alone, on Mac |
| Luminar Neo + HDR Merge extension | Yes | Yes | $49 extension on top of Luminar Neo | You want a full editor too |
If merging is your only problem, HDR Forge at $9.99 is the sensible purchase. It groups brackets automatically by exposure, timestamp and filename, batches hundreds of sets, and has Real Estate, Interior and Exterior presets. We are building a Mac app in this space and we still think that. Do not spend more to solve a problem that costs ten dollars to solve.
If you need Windows, or you need tone-mapping control, buy Photomatix. €89, one-time, and the licence does not expire.
The part none of them do
Merging is one step. On a property shoot it is not the step that eats the evening.
After the merge you still straighten verticals, neutralise colour casts that differ from room to room because the lighting differs from room to room, export at portal sizes with sequential names, and rename everything into one folder per address. That is the work. The merge is the fast part.
We are building Hauscrate for that second half. It is a Mac app. You drop a folder from one shoot, and it treats the property as the unit of work rather than the image: brackets grouped per room, merged with exposure fusion, verticals straightened, colour cast removed per room, exported at portal sizes with sequential names in a per-property folder. Everything runs on your Mac.
If that sounds like your evening
Hauscrate is in development. It is not finished, there is no release date, and nobody is using it yet. €99 one-time when it ships.
Put your email on the early-access list and we will write when there is something to try. No other mail.
Join the early-access list →