Originally posted by Marc Sabatella I'd sugest browsing this forum - the topic is discussed practically once a week. Bottom line: the formats contains the same data but in different containers. The PEF container has the advantage of being smaller than the DNG files creates by the camera, but you can always create compressed DNG files later using the Adobe DNG Converter that are smaller still. PEF files require metadata to be stored in sidecar files, DNG allows it to be stored within the image file itself. Some believe PEF will be more liekly to still be supported in the future, some believe DNG will.
Future support isn't really all that much of an issue, but I'm putting my money on DNG rather than PEF. I have software right now that works with DNG, I'm not seeing that changing in the future.
The nice thing about DNG is that older software can be used with newer cameras. As was posted in another thread, a new K-7 user can't get his PEF files to read with CS3. This is something that will never be rectified by Adobe, as they have moved past that program and are no longer issing rar converter updates for it.
OTOH, I was able to open my K20 DNG files with Adobe Photoshop 7, and I expect my K-7 DNGs will open on that older software as well.
This is a good thing, as I don't have the most up to date software on all my computers, but it is nice to be able to keep working in the event of a machine failure without having to load anything new.
The K-7 DNG files are smaller than the PEF files by a very small amount (perhaps 200K), so what was true in the past about file size is no longer true.
With storage being as cheap as it is, I always thought the file size thing was a pretty specious arguement anyway.