Pentax K10D Operating Manual page 53

51
When File Format is RAW
With q, you can record in the versatile JPEG format or the high
quality and editable RAW format. For RAW file format, you can select the
PENTAX original PEF format or general-purpose DNG (Digital Negative)
format designed by Adobe Systems. On a 512 MB SD Memory Card, you
can record up to 29 images in PEF format or DNG format.
1 Setting the File Format (p.122)
2