3F (short for Flexible File Format; also called FFF, Imacon 3F, Hasselblad 3F, etc.) is a raw image format produced by some Imacon and Hasselblad scanners and digital cameras.
It is based on TIFF. If you display a 3F file in a TIFF viewer that does not understand 3F, you might only get a low-resolution version of the image.
It is the predecessor of Hasselblad 3FR, but is still used by the Hasselblad Phocus software. "If developed in Phocus, 3FR files become Hasselblad 3F files – denoted by each file now bearing the suffix “.fff”. If developed by other RAW processors, the 3FR files are not converted to 3F but can be exported directly to TIFF and PSD according to requirements."
If TIFF tag 46275 is present in the first IFD, it's likely a 3F file.
- http://www.rawzor.com/downloads/samples2_original.zip → IMACON_IXPRESS.FFF
- 3FR vs. FFF (broken)