Originally posted by boriscleto so there is no reason to use PEF over DNG even if your software supports PEF
The two are supposed to be quite equivalent. My understanding is that Pentax DNG is just a PEF in a DNG wrapper. (The DNG spec allows for that.) That being said, there is one strong case for using PEF over DNG. With Lightroom there is the option to save the catalog metadata (develop and library stuff) to file. With DNG, the original file is overwritten with the metadata included in the file. With PEF, it is written as an XML "side-car" file.
The difference is important if:
- You want to retain the original RAW files with all data untouched
- You want to have lightweight settings files to share to/from a service bureau/printer.
The second case is more common. There may be a way to force Lightroom to write to side-car files only, but if there is, I have not found it.
Steve