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Cleaning a Nikon RAW is different from cleaning a Canon or Sony one, and it is better you hear it from us first: one identifying field, the camera serial number, is deliberately left in the file. The rest of this page explains the reason, what is removed around it and what we saw on a real NEF.
What is in a NEF
| Section | Fields | Reveals |
|---|---|---|
| EXIF and IFD0 | Software, Artist, Copyright, UserComment, DateTimeOriginal, CreateDate, ModifyDate | Firmware version, a name or remark, the moment of capture |
| Nikon maker notes | SerialNumber, ShutterCount, white balance, lens data, shooting settings | The individual body, its wear and its setup |
| GPS | Latitude, longitude, altitude, time | The place, on bodies with GPS or a connected unit |
| Previews | A JPEG preview, often a bigger one in the raw directory | Small images that might hold their own metadata |
| XMP and IPTC | Keywords, captions, ratings | Added by editing software |
Why the serial survives
ExifTool's documentation describes the Nikon serial number as the key for decrypting other maker-note information, and notes that a new value makes ExifTool re-encrypt that data. ExifTool can do this safely. Whether every other converter copes with a changed or missing number we cannot confirm, and a wrong guess gives the user a file that opens with wrong white balance or no lens data, which is worse than a serial that stays.
So SerialNumber and ShutterCount stay and everything else listed above goes. Be aware of what that means: the serial identifies a camera, and anybody who can link it to you from a purchase record or a warranty registration can link the files too.
Result on a real Nikon file
The sample was a public CC0 file from raw.pixls.us: a 5.8 MB Nikon D40 NEF cleaned by the production code and then examined with ExifTool.
- Before: a firmware string in
Software, three dates and the serial number. The capture date also appeared at a second, misplaced spot in the first directory, which caused an ExifTool warning; that copy is removed and the warning is gone. - After: the firmware string and all dates gone;
SerialNumberand the shutter count remain. - Picture data: raw data and both JPEG previews were identical byte for byte.
- Maker notes: all 82 tags, white-balance levels and lens data included, read the same as before.
- Validation: ExifTool reported the cleaned file as OK.
- Compression: Nikon's lossy raw compression is copied like any other data.
Neither preview in this file carried personal tags, so both were left untouched. When a preview does hold a copy of the camera's metadata, it is rewritten without it, or removed if the format will not accept a rewrite.
Summary of what goes and what stays
| Removed | Kept |
|---|---|
| All GPS tags | Make, model and lens information |
| Capture, creation and modification dates | Exposure, white balance and shooting settings |
Software, Artist, Copyright, UserComment | Nikon maker notes with SerialNumber and ShutterCount |
| XMP and IPTC | Sensor data and previews |
| Personal tags in embedded previews | Colour data a converter needs to develop the picture |
Reduce what the camera writes
- Keep copyright information blank in the camera menu unless you want your name in all files.
- Switch off GPS, or the location copied from a paired phone, when you do not need geotags.
- Remember that the serial is in every file: public RAWs from one body can be tied to each other.
Cleaning a NEF
- Start without an account. Guests may clean 5 RAW photos a month, a free account 10.
- Add the NEF. NRW files from compact Nikon cameras work as well.
- Wait while the server removes fields, handles previews and scans the result.
- Read the report. On a Nikon file expect
SerialNumberand nothing else.
Maximum file size: 25 MB for guests, 25 MB on a free account, 100 MB on Starter, 500 MB on Pro and 1,000 MB on Business. The small D40 sample fits a free account, but NEFs from newer bodies are often much larger than 25 MB. Originals are deleted when cleaning finishes and clean copies within 15 minutes. See pricing.
exiftool -a -G1 -s -SerialNumber -ShutterCount -artist -copyright -software -alldates -gps:all clean.nefAll RAW formats are covered by the RAW photo metadata remover. For Canon, Sony and DNG results see the CR2, ARW and DNG pages.
Questions
Why does the report say one field is left?
That field is Nikon's serial number. It is a key for the encrypted part of the maker notes, so it is kept and named instead of risking a file that decodes wrongly.
Can the serial number identify me?
It identifies a camera, not a person. Someone who can match the number to you through a receipt or registration can connect it to your files.
Will white balance or lens corrections change?
No. In our test all 82 Nikon tags, including white-balance levels and lens data, were identical before and after.
What about the shutter count?
It stays, as it is part of the decryption key. It shows how much a camera has been used, not who owns it.
Does the picture itself change?
No. The raw data and both previews of a real NEF were byte for byte identical after cleaning.
Is GPS removed?
Yes, completely, along with dates, firmware text and artist, copyright and comment fields. The Nikon sample had no position recorded; GPS removal was confirmed on a phone RAW file.
Is my NEF uploaded?
Yes. RAW needs ExifTool, so the file goes over HTTPS to our server. The original is deleted when cleaning ends and the clean copy within 15 minutes. We never open the picture.
Are NRW files supported?
Yes, in the same way.