Convert NEF to TIFF

No other raw format on this site offers as many ways to store the same frame. A Nikon body can write the sensor data uncompressed, lossless compressed, or lossy compressed, at 12 or 14 bits per channel, and newer Z bodies add high-efficiency variants on top. The difference between the extremes is enormous — a 45-megapixel frame can be 90 MB or 25 MB depending on which you picked.

None of it reaches this conversion. The camera writes a finished JPEG preview alongside the sensor data, and that preview is produced the same way whatever the raw settings are. Convert two NEFs of the same frame shot at different compression settings and you will get the same picture at the same size. It is the most direct demonstration available that this page does not develop your raw file, and it is worth knowing before you assume the setting you agonised over is being honoured here.

An NEF opens with the bytes 4D 4D 00 2A — the letters "MM" followed by the number 42 — which is the header of a big-endian TIFF. Nikon built NEF on the TIFF structure, so a program with a TIFF parser can walk the directories and read the tags. The TIFF this page writes opens with exactly the same four bytes.

What differs is everything after them. An NEF’s image data is undemosaiced sensor readings on a Bayer grid: one colour per photosite, meaningless to any reader that does not know how to reconstruct the other two. The TIFF’s image data is finished RGB, three channels per pixel plus an alpha channel, ready to display. Same envelope, entirely different contents, which is why software that "supports TIFF" still cannot show you an NEF.

Be honest with yourself about the brief. When a retoucher or a picture desk asks for TIFF, they are usually asking for a 16-bit file developed from the raw with a stated colour profile, because that is what survives being pushed about: skin retouched, a sky replaced, a colour grade applied. What this page produces is an eight-bit rendering of the camera’s own JPEG, with the Picture Control already applied and no profile attached.

That does not make it useless. For a picture that needs cleaning up rather than reinterpreting — a logo removed, a crop, a small blemish — it is entirely adequate and much faster to produce than an export from NX Studio or Lightroom. For anything more, the better answer is to send the NEF and let the person with the calibrated monitor decide how it should look. Ask which one it is; it takes a message and saves a re-delivery.

Four bytes a pixel, no compression, plus about a kilobyte of header. A 24-megapixel frame — 6,048 by 4,024 on a Z6, 6,016 by 4,016 on a D750 — is 97 MB; a 45-megapixel D850, Z8 or Z9 frame at 8,256 by 5,504 is 182 MB; a 20-megapixel D500 at 5,568 by 3,712 is 83 MB.

That is the whole trade TIFF makes and it is not subtle: a compressed NEF that occupied 50 MB becomes a TIFF that occupies 182 MB, with no more picture in it than before. Plan the delivery around it. A shoot of two hundred frames delivered this way is not going in an email, and file transfer services meter by the gigabyte.

TIFF is less a format than a filing system for images, and readers agree on less of it than the name suggests. LZW compression is patent-free and universally supported; Deflate is not universally supported; JPEG-in-TIFF is a JPEG in a TIFF wrapper, which defeats the point of asking for a TIFF. Tiles, strips, planar configurations and predictors all have variants that some readers handle and some do not.

What is written here is the plainest option: no compression, one strip, photometric RGB, eight bits per sample. It is the dialect nothing refuses, and it is chosen precisely because the person receiving a TIFF is usually feeding it to a specific piece of software whose tolerances you do not know. If your recipient asks for LZW, resaving the file in any editor produces it with identical pixels.

The 14 bits per channel your Nikon recorded were reduced to eight by the camera when it wrote the preview, so eight bits is what the TIFF holds. TIFF as a format allows 16 and 32, and this conversion has nothing to put in them.

Where this bites is any adjustment that stretches the tonal range a long way. Lifting a shadow region by two stops in eight bits spreads a small number of levels across a large range, and the steps become visible as banding — the same edit in a 16-bit development of the NEF has four times as many levels per stop to work with and absorbs it. If the file will be graded rather than viewed, that is the argument for developing the raw properly instead.

This conversion writes no ICC profile, so any reader will assume the numbers are sRGB. Nikon bodies have a colour space menu with sRGB and Adobe RGB in it, and plenty of photographers set Adobe RGB years ago on the advice that it is "wider" and have not thought about it since.

If that is your camera, the preview inside the NEF describes Adobe RGB colours and the TIFF will hand them over unlabelled, to be read as sRGB. Saturated colours come back visibly duller. It is the single most common way a technically correct delivery looks wrong on someone else’s screen, and the fix is either to shoot sRGB for files going out this way or to develop the NEF in software that can convert the profile properly.

Decoding and re-encoding drops the metadata entirely. Lens, focal length, aperture, shutter speed, ISO, capture time, copyright field and any GPS coordinate from a body or a paired phone are absent from the TIFF, even though the format has a defined slot for all of them.

For a delivery that matters in both directions. A picture desk that expects the capture data to travel with the frame will not find it, so it has to go in the accompanying sheet or the file name. On the other hand a location shoot no longer publishes where it happened, which is a genuine consideration for anything shot at a private address.

The converter takes the largest embedded JPEG above 640 by 480 and refuses anything smaller, on the grounds that handing over a thumbnail is a worse outcome than a clear failure. On a file straight from a Nikon this never happens; the camera writes a full-resolution preview.

When it does happen, the file has usually been through something. NEFs rewritten by third-party software, recovered by an undelete tool, or truncated by a card removed mid-write can have a damaged or missing preview. The remedy is the original card copy if one exists, and a real raw decoder if it does not, since the sensor data is still there even when the preview is gone.

The scan, the decode and the TIFF assembly all happen in the page. Nothing carrying the image is transmitted, which the network tab will show and a disconnected machine will prove, and which matters when the shoot is embargoed, commissioned or not yours to publish.

Input is accepted up to 100 MB per file on the free tier. That covers every compressed NEF comfortably and most uncompressed ones; a 45-megapixel uncompressed 14-bit frame can approach the limit, in which case shooting lossless compressed — which changes nothing about the picture — brings it well under.