Advanced Settings
Batch merges, calibration frames, output options and troubleshooting.
The Advanced Dialog
Choose Merge Raw Files (Advanced) for batch processing and optional corrections. The defaults match the simple dialog.
Batch Mode
- Merge All Photos: one DNG from the whole selection.
- Merge Each Stack: one DNG per Lightroom stack. Lightroom's Auto-Stack by Capture Time can help group bursts.
- Merge Each Directory: one DNG per folder.
- Process Each Photo: apply corrections separately to every photo, without merging. Available with No Alignment - Tripod.
Hot Pixel Removal
Repairs hot pixels without a dark frame. Leave it on Automatic for most photos. Choose Night Sky to force repair while protecting stars, or Daylight Long Exposure for daytime scenes. Avoid Daylight for stars or tiny bright subjects. Off disables this repair; supplied dark frames still apply.
Dark Frame(s)
Use lens-cap exposures taken at matching settings and temperature to remove hot pixels. Particularly useful for long exposures and astrophotography.
Flat Field Frame(s)
Use photos of an evenly lit blank surface, taken with the same lens and aperture, to correct vignetting and corner color shifts. Useful for copy and reproduction work. This feature is experimental; check the corners of the result.
Choosing Dark and Flat Frames
Filter the selected Library photos by Filename, Directory, Color or Stars, or choose a File on Disk or Directory on Disk. Library calibration frames are excluded from the main merge and shared across batch groups. Files chosen from disk may need importing into the catalog; MergeRAW asks first, and they remain there afterwards.
Demosaic Mode
- Auto: the default for most photos. For X-Trans merges that need RGB processing, it uses Adobe's demosaic when DNG Converter is installed.
- Sharper: try it for finer detail, or as an alternative raw conversion for a single photo. On X-Trans, it also applies localized false-color and moiré repair to repeating detail. This adds processing time.
- Safe: try it if you see color artifacts. Requires Adobe DNG Converter and takes longer.
Hot Pixel Removal and Demosaic Mode are unavailable with Pixel Shift.
Output Options
- Remove Lens Profile: removes the built-in profile and lens correction settings from the merged DNG. Use it when you want to handle lens correction yourself; distortion and vignetting may become visible. Off by default.
- Force Mosaic Output: writes supported Bayer merges as a lossless mosaic DNG, useful when Lightroom AI Denoise gives a linear night-sky DNG a purple cast. Align Stars already uses mosaic output in Auto/Safe. This option is unavailable for Pixel Shift and focus stacking.
- Update Exposure EXIF: updates ISO and exposure time to describe the combined exposure. Turn it off to retain source values. On by default; always disabled for Pixel Shift, Darken and both focus-stacking modes.
The Advanced dialog remembers these choices. The simple dialog always uses the defaults.
Settings and Troubleshooting
Open File › Plug-in Manager › Ryan's Raw Tools for settings.
- Scratch folder: choose a fast drive with plenty of free space for temporary files.
- Language: follow Lightroom's language or choose another for MergeRAW dialogs.
- Output compatibility: the default gives the smallest files. Use Common (DNG 1.7.0) for DXO PhotoLab, or Compatible (DNG 1.4.0) for older software. Image quality is unchanged.
- Open Log: shows what happened in the last merge, including skipped frames. Save it before running another merge.
Night Align normally uses fewer frames than you selected. If it drops too many, try a faster shutter speed. Star tracking needs enough visible stars in most frames; cloud or very short exposures can prevent alignment.
For help, email mergeraw@mackman.net with MergeRAW in the subject and attach the log.