ORF file are generated by Olympus cameras.

# MIME type

image/x-olympus-orf

# Organisation

It if a TIFF file with a custom magic at the beginning: MMOR, IIRO or IIRS instead of the TIFF magic.

IFD 0 contain the main image. IFD 1 contain the 160x120 preview. Some file don’t have the preview outside the MakerNotes.

Another peculiarity is that StripOffsets and StripByteCounts are arrays for the E10 files, unlike the others. Still consistent with the TIFF/EP standard.

# Compression

Sometime the CFA does not look like it is compressed but seems to be organised weirdly. E400 has uncompressed CFA.