What does this format store?+
NEF is Nikon Electronic Format, Nikon’s raw image representation. It stores capture data with camera, lens and exposure information so a raw processor can develop an image after capture. White balance and other rendering decisions can be interpreted later rather than being fixed only in a camera-generated JPEG.
How does compression affect quality?+
Nikon documents uncompressed, lossless-compressed and compressed modes on different cameras. Documented models can offer 12- or 14-bit recording. These are camera settings, not one universal NEF property; compressed without the word lossless should not be assumed reversible.
Is every NEF losslessly compressed?+
No. Nikon offers different modes depending on camera. Read the recording settings and model manual; both precision and compression can vary.
What should I check before opening the file?+
Check the exact camera model and recording mode in the processor’s support list. Raw support is model-specific, even when the extension is recognised. Viewing an embedded JPEG preview does not prove the sensor data has been decoded.
What changes when I export to another format?+
Raw-to-image export develops the data: white balance, colour mapping and tone become part of the pixels. Grayscale, palette and SDR targets can discard additional information. Keep the original; converting a rendered image back into a raw container cannot reconstruct the capture.
When is this format useful?+
Use the raw original for repeated photographic development when exposure interpretation and colour decisions need to remain flexible. Export JPEG for an opaque delivery image or a suitable high-precision raster for further editing. Those exports bake in processing choices and cannot recreate the original sensor data, calibration or all vendor metadata.