JPG-Repair Toolkit allows you to recover data from corrupted NEF photos (JPEG). Nikon RAW photos (NEF) contain the raw, ‘undeveloped’ sensor data. JPG-Repair Toolkit can process multiple Nikon RAW files (NEF) files in batch.
High resolution, full frame JPEG from a corrupted NEF photo.
Commonly Nikon RAW photos embed one or more JPEGs: a low resolution thumbnail, a medium resolution preview, and in many cases a full frame preview. I have seen NEF photos were a full frame JPEG was embedded even though the camera was set to shoot at a lower resolution! Using JPG-Repair Toolkit you can extract the full frame preview.
Technically JPG-Repair Toolkit does not repair NEF photos, it extracts JPEGs already embedded! Of course having undeveloped and unprocessed RAW data is probably preferable, the full frame JPEG is hardly worthless.
How to recover data from corrupted NEF photos using JPG-Repair Toolkit
Browse to the folder containing the corrupted NEF file(s) and select files you want to extract embedded JPEGs from.
For RAW files select a minimum resolution, probably > 1.9 (MP) to skip lower resolution thumbnails and medium sized previews.
Many RAW photo formats contain a full frame JPEG. If this setting is set to a too low value, JPG-Repair may simply extract the medium sized preview. If too high it will skip every JPEG it comes across.
JPG-Repair will get to work and save files using the following format: OriginalName-1.JPG.
For each file it is able to repair it will show a preview and certain details such as resolution. Note that the free version only saves scaled down BMP images!