NEF

What is an NEF file?

Nikon raw capture. TIFF based, which is why generic tools half-open it and get the colours wrong.

What NEF is

NEF is a container: a wrapper that holds streams encoded by something else. It stores a grid of pixels, so enlarging it past its own resolution softens it. It is used for photography and editing.

The extension is .nef, and the full name is Nikon Electronic Format. Both matter less than what the file can hold, which is what the rest of this page is about.

Where NEF came from

Nikon published it in 1999. It comes out of Nikon digital SLRs and Z-series mirrorless bodies bodies.

A format that has been readable for that long is a format worth trusting with something you want back in ten years.

The specification belongs to its vendor

Reading it outside the vendor’s own software depends on work done by other people, usually by inspection rather than by documentation. That mostly works and occasionally does not, which is the reason to convert anything you intend to keep.

Nothing is thrown away

NEF stores its content exactly. Saving it again changes nothing, so it can be opened, edited and re-saved as often as you like without accumulating damage — which is what makes it a working format rather than a delivery one.

It cannot be transparent

NEF has nowhere to record transparency. Anything transparent in the source is filled with a solid colour on the way in — white, unless something chooses otherwise.

Colour it can describe

Up to 14 bits per channel. It can work in RGB.

More than eight bits per channel is what stops a gradient from stepping when it is edited, which is why it matters in a working file and rarely in a finished one.

What opens NEF

Adobe Lightroom, Nikon NX Studio and darktable read it, and so do most programs of the same kind.

If a file will not open, the format is rarely the problem — it is more often that the program predates it. Converting to something older is the reliable way past that, and it is what the rest of this site is for.

Opening it in a browser

No browser reads it.

That is the single most common reason to convert it: not that the format is bad, but that the place you want to show the file cannot read it.

What it can carry besides the content

NEF can hold EXIF, XMP and GPS coordinates.

The GPS coordinates are the field worth thinking about before sending a file anywhere: they say where the photograph was taken, and almost nothing warns you that they are still in there.

It is a working format

NEF is meant to be opened and changed. Keep the file in this format for as long as the work is going on, and export from it whenever a finished copy is needed.

What goes wrong with it

The recurring complaints: programs often show an embedded preview rather than the real data and support outside its home ground is uneven.

None of these is a reason to avoid the format. They are the things worth knowing before you are surprised by one, which is a different claim and a more useful one.

The facts, in one place

Identifiers and provenance for the NEF format.
Extension.nef
Media typeimage/x-nikon-nef
Published byNikon
First published1999

Converting NEF to something else

Formats worth considering instead of NEF