Lightroom Classic#

lapstack.lrplugin sends the frames of a focus stack out of the catalog to the lapstack command-line tool and brings the stacked image back in, stacked above the first frame. It is the round trip Helicon Focus and Zerene Stacker offer.

Requirements: Lightroom Classic 6 or later, and the lapstack command-line tool installed. The plugin does not contain the engine; it drives the binary.

Installing#

1. Copy the lapstack.lrplugin folder somewhere permanent — Lightroom reads it in place.
2. File › Plug-in Manager › Add, and choose that folder.
3. In the plugin's section of the Plug-in Manager, set the path to the lapstack executable with Browse…, and set the stacking settings.

Settings#

All of these live in the Plug-in Manager's section, and the same rows appear inside the Export dialog.

Two ways to run it#

Both doors run the same thing.

Library › Plug-in Extras › Stack with lapstack#

Select the frames of one stack — in order; sort the grid by capture time — and choose the menu item. No dialog opens.

The frames are rendered with the Plug-in Manager's settings (a sixteen-bit TIFF in the chosen color space, or the originals, which is what a DNG output wants) into a temporary folder, lapstack runs over them in the order of the selection, and the result is imported and selected, stacked above the first frame.

File › Export, Export To: lapstack#

The Export dialog, with Lightroom's own File Settings, Image Sizing, Output Sharpening and Metadata sections, plus the plugin's own section carrying the same lapstack settings. The Location and Naming sections are hidden, because Lightroom renders into a temporary folder it removes afterward.

Choose Original in File Settings to hand over the raws as shot; choose sixteen-bit TIFF otherwise.

The settings are saved in the export preset, so different subjects can have different presets. Closing the dialog with Export also makes those settings the menu item's.

Where the result goes#

Next to the first frame, as <first>_stacked.<ext>, with lapstack's log beside it as <stem>.lapstack.log. A failure shows the log's tail.

A result Lightroom will not import — an unsupported format produced by something in the extra options — is left on disk and reported rather than silently lost.

One selection is one stack#

The plugin treats the selection as a single stack. To stack several at once, put --split in the extra options and use the output templates to number the results.

The run cannot be interrupted once lapstack has started — Lightroom's LrTasks.execute blocks its task. The progress bar's cancel takes effect before the run and after it.

Platform notes#

On Windows the command line is wrapped in one extra pair of double quotes, because LrTasks.execute hands it to cmd.exe, which strips the outermost pair — a long-known quirk of the SDK. On macOS every argument is single-quoted for sh.