NEF file format

NEF means Nikon Electronic Format is raw image file format which is use to store digital images clicked by Nikon Digital Camera. This is mainly based on another file format – TIFF and has two subIFD. The first one store full image with some loss, in JPEG format and second one store complete RAW image without any loss, in compressed form. Raw image mainly contains unprocessed image files which have enough informtion including image's metadata(camera setting details, type of lens and other details) for developing images in other file format like JPEG, TIFF, BMP, JPG and many more. This is also called as digital negatives which are “dump” of CCD content. Because of these are raw in nature and contain more information due its bigger size, gives photographers wide scope to develop image with more improvement on image quality, color balance, better control over color depths, image defination, shadow areas, exposure etc. It is mostly appreciated by photographers due to its high image quality and least lossness of color resolution and defination of image. Their wide acceptance over JPEG and TIFF images are due high quality of image, compression without loss or no compression in general. It holds either 12 bit or 14 bit data which results in far better tonal range over 8 bit of TIFF or JPEG files.

NEF header

The NEF header is a standard TIFF header.

OffsetLengthTypeDescriptionValue
0x00001short byte orderUsually 0x4D4D / "MM", except for E5700 ( 0x4949 / "II" )
0x00021shortTIFF magic value0x2a
0x00041longTIFF offset8
0x0008IFDfirst IFD

Contents of Nef File Format

Normally, Nef file contains the information for developing a raw image into viewable image acquired from sensor's data of camera. These generally follow a familiar patern i.e.:

  • File header which contains the details of byte-odering of file, file identification details
  • Metadata of camera sensor required to execute its data. It include sensor's size, CFA's attributes and color profile
  • Metadata of image required for inclusion in database or in CMS environment. It include exposure setting, lens/scanner/camera model, date of shoot or scan
  • Thumbnail of an image
  • Store reduce size of image in JPEG format which is optional

Nef file have various saving options:

This mainly depends on camera type and have three different category for saving these files:

  1. Uncompressed: This category save files without any compression and have largest details of image.
  2. Compressed: This category save files in compressed format and take minimal memory space for storing images. There is only a little visible differnce in compressed and raw Nef files.
  3. Lossless Compressed: This category save files in compressed format which haven't any visibility difference for raw Nef files. This allows a wide range of image-editing options and provide it to resave in uncompressed format again.

Finally, Nef File Format is supported on Microsotf Windows and Mac operating system and its files have the extension .nef.