PEF or DNG?

[Galad]

Sorry for reiterating this issue again - I know this has been up for discussion before (more than once), but I'm not quite satisfied with the answers I got in the old threads, so I'm going to make it more specific:

• I shoot RAW with a Pentax K-7, where I have the option to save either the Pentax specific file format PEF or Adobe's DNG in camera.
• I'm using Lightroom for RAW development.

I've seen claims that edits are stored directly in the DNG file, which some seem to think is an advantage. I don't think it is, I want to keep the original file. Luckily, it seems it's not quite true, I have chosen to keep edits separately in LR3, and this seems to apply for both formats. One difference I've seen so far is that if I do a "Save Metadata to File", then it's written directly into the DNG file (which I don't like) but into a separate XMP file if it's a PEF (which I like - it's XML, so it's possible to extract and handle independently). Another difference is that with DNG there's an additional Profile option, "Embedded", as seen in another thread.

So, given all this, any thought on which I should prefer (in camera)? Will I lose any data if I use DNG? Will the file process differently in any way?

 

[Garbz]

Just to be clear, the edits are not actually overwritten in the DNG. The edits are added to DNG metadata and the original RAW data is unchanged.

- Will you lose data in DNG? Well if the camera implemented it properly then no you should have just as much quality in a DNG file as you did in a PEF.
- Will the file process differently? Not really. A RAW converter will convert the file into a common working format and then apply settings identically if it's a RAW or PEF.

The only real difference between them and the main advantage of the DNG is that the format is open and extensible. It can hold a 10bit D200 RAW data or a 14bit Canon 1DmkIII RAW data. The open bit is the key. If you were to place bets on which format you will be able to read in Photoshop CS27 in 40 years; an Adobe supported openly specified file which some nerd may have written a converter for because the spec was available, or an obscure file in an obscure format belonging to a Camera which wasn't a terribly well selling camera all the way back in the first decade of the century, I know where I'd put my money.