RAW highlight recovery and exposure shift for a whole folder

Published October 25, 2026 · 6 min read

A RAW file holds more than a finished JPEG shows. Where one colour channel of the sensor filled up, as in the sky behind a backlit subject or the windows of a room, the usual development cuts the area to flat white. Contenta Converter 9.0.44 adds the controls that decide what happens there. They come from LibRaw, the engine that develops the RAW files, and they sit in the wizard's RAW card and on the command line.

Bright areas: four ways to treat blown highlights

Bright areas is in the Highlights section of the RAW card. It decides what happens where the sensor ran out of room.

Keep all and Rebuild switch automatic brightening off, so the picture comes out darker. The RAW card says so under the list: raise the exposure to make up for it.

What each mode did to one test frame

Measured during development on a Nikon NEF test frame, saved as JPEG at quality 90. Average brightness is on a 0 to 255 scale; blown pixels are pixels with at least one colour channel at pure white.

Every mode other than Clip left 7 to 12 times fewer blown pixels. On a DNG test file, Keep all and Rebuild took the average brightness from 97 down to 30, which is why the exposure needs raising after them. Blend kept it at 97.

Exposure shift: brighten dark interiors and keep the windows

Exposure now works like the exposure setting on your camera: the shift is applied to the RAW data before it is developed. One stop up doubles the light, one stop down halves it. Use it for a church interior, an evening reception or any set shot too dark.

Tick Protect highlights when you raise the exposure. Bright areas, such as the windows of that interior or the lamps in the room, keep their detail instead of turning flat white. It acts only on a positive exposure.

On the NEF test frame at +1 EV, Protect highlights cut the pixels that were pure white in all three channels from 2,957,214 to 685,049, while the average brightness moved only from 206 to 203.

Profiles saved by earlier versions keep their older exposure method, a brightness multiplier applied after development, so a saved profile gives the same result as before.

Brightness: Automatic, On or Off

LibRaw normally brightens each frame from its own histogram, so that 1% of the pixels reach white. Brightness, in the Exposure section, controls that step.

• Automatic (default): on for camera RAW files such as NEF, CR2 and ARW and for most DNG files. Off for DNG files that carry their own rendering, and off while an exposure shift is applied, because it would cancel most of the shift.
• On: always brightens, even with an exposure shift. The shift then has less effect.
• Off: the picture as exposed, darker, with no adjustment per frame. A bracketed series keeps its exposure differences.

The Clip % box next to it sets the share of pixels allowed to reach white, 1% by default. A higher value gives a brighter picture: on the DNG test file, 5% raised the average brightness from 97 to 127.

Which setting for which shot

Example: a folder of backlit beach portraits

A session shot into the sun: faces a little dark, the sky blown behind them. One batch handles the whole folder.

1. On the Files step, click Add Folder and pick the folder of RAW files.
2. Click Next: Operations. When every file is a RAW, Convert and RAW Processing are already on.
3. Click Next: Configure, choose JPEG in the Convert section and open RAW Processing.
4. Under Highlights, set Bright areas to Rebuild and leave the strength at 5. Under Exposure, move the slider to +0.7 and tick Protect highlights. Leave Brightness on Automatic.
5. Click Generate RAW Preview to check one frame; the preview develops again after each change. Then choose the output folder and click Start Converting.

From the command line and MCP

The contenta command line has the same controls on convert, batch and watch. The example above in one line:

contenta batch "D:\Shoots\Beach" -o "D:\Shoots\Beach-jpg" -f jpg -q 90 --raw-highlights rebuild:5 --exposure 0.7 --raw-protect-highlights

--raw-highlights takes clip, unclip (Keep all in the app), blend or rebuild:3 to rebuild:9. --raw-auto-bright takes auto, on or off, and on:0.02 also sets the share of white pixels. --exposure is now an exposure shift; add --raw-exposure-mode gain to get the output of earlier versions.

Through the MCP server, convert_image and batch_convert take raw_highlights, raw_exposure_mode, raw_protect_highlights and raw_auto_bright with the same values. More about the CLI and the MCP server

Questions

Related: how to convert RAW files to 16-bit TIFF for editing

How to batch convert Canon CR2 and CR3 RAW files to JPEG