NEF is a format for original, raw graphic files created by Nikon technology. Accordingly, the developer of the format is also the specified company. The name of the format is an abbreviation for Nikon Electronic Format. At the same time, NEF format files received by Nikon cameras of different models can have a different structure, so compatibility is not guaranteed. Nikon's graphic editors are geared towards supporting specific camera models. When creating a file, the data comes directly from the matrix. NEF files are of good quality and contain metadata, and therefore take up a lot of space.
BMP is a graphic format that allows you to store bitmaps as a bitmap based on single-layer rasters. It was developed by Microsoft. She also implemented it in the Windows operating system. The BMP format (English Bitmap Picture) is used in the work of many programs, since its support is integrated into Windows and OS / 2. Files of this format can have the extensions .bmp, .dib or .rle. The BMP graphics format has often changed. From the very beginning, the image structure was built by combining small squares, that is, pixels, each of which is capable of containing data about what color depth is. It happens to be 1, 2, 4, 8, 16, 24, 32, 48 bits per pixel. The size of the final image depends on the bitness. The BMP file format still looks like a monster, since it has large sizes. After all, the image is uncompressed, which can not be said, for example, about the JPG format. Any Windows operating system has the means to open such images. The main editing tool has always been Paint - the native Microsoft program that is in every version of Windows. In BMP, images are stored in their original form, but compression algorithms can also be used. Let's say BMP provides quality support for RLE compression.