Originally posted by newmikey Assuming the camera firmware is capable of generating DNG as well as PEF, both are 100% proprietary to Pentax and both contain metadata that existing Adobe software may not correctly interpret until it is updated. Assuming you take either the PEF and convert it on your computer to DNG, you will loose that proprietary metadata. Any DNG manipulated by software on your PC and restored will likely strip that same proprietary data.
Given a Pentax camera which can use either PEF or DNG natively, both formats will contain hinting and (meta)data which is proprietary to a new camera model, neither format will be converted correctly by 3rd-party software (including Adobe's) until it is updated to take the new features into account notwithstanding the fact that Adobe software may be able to extract some image data early on (although even that has proven troublesome in the past). DNG as a format is no more "futureproof" than any other raw format in use today.
My aim isn't to change what you do. I'm trying to establish some facts that will stand up to scrutiny.
I believe the following is true:
From when Pentax began to use DNG in cameras, they have continued to support DNG in
all subsequent cameras that support raw
But the converse does not apply. There have been a number of Pentax cameras that support DNG but
not PEF.
Not the
major K-Mount cameras, but some nevertheless: Q-Series; K-500 (?); K-30 (?); MX-1 (?). Perhaps others.
Edit: Whoops! I've just that "Not a Number" was there before me!
https://www.pentaxforums.com/forums/6-pentax-dslr-discussion/378298-raw-file...ml#post4501388
My interpretation is that DNG is now the Pentax main and consistent raw file format, and PEF is an optional extra for historical purposes.
(Ricoh uses DNG, not its own raw file format if they ever had one, for its own cameras that support raw. Such as the GR II, and I'm confident for the GR III next year).
When Adobe software handles a DNG from out of a camera, it uses the published DNG metadata in the file, but not any "secret sauce" that is not in the DNG specification.
(What actually happened is that Adobe identified what it needed to do its raw conversions, and designed the DNG metadata to match!)
I believe the DNG format has never been influenced by the needs of a Pentax camera. Those cameras have used DNG "as-is".
(I believe this leaves something to be desired when Pixel-Shift is used. But that appears to apply whether Adobe is processing a PEF or a DNG).
I accept that there is probably some non-Adobe software that supports PEFs (once they have reversed engineered them) but not DNG.
At one time this was typically because they had already done much of the work to support PEFs, and avoided the extra generic work to support DNGs for
any cameras.
I'm not sure what reasons they give nowadays.
Something interesting about DNG is the amount of material available free
with no questions asked and no Non-Disclosure Agreements.
Obviously the DNG specifications!
But also the DNG SDK. It comes with both executable programs and lots of C++ files. I often use it to have a peek inside out-of-camera DNGs, hence the DNGs from my own Pentax cameras and also the Ricoh GR II.
I've been using DNG for over 14 years. I've published a huge amount about it:
DNG - Digital Negative format DNG » Barry's blog
In the unlikely event you feel the need to read it, I would welcome being informed of any errors you find.
---------- Post added 30th Oct 2018 at 04:05 PM ----------
Originally posted by stevebrot .DNG is Adobe's proprietary solution to provide a common currency between its various tool offerings.
Adobe offered DNG to ISO years ago. ISO TC42 WG18 were expected to publish it as an ISO standard. It would then not belong to Adobe in any sense.
For some reason, (my contacts won't say why), this process appears to have stalled.
Adobe did the same with TIFF, (which they "own"). Unfortunately ISO mangled it to become TIFF/EP, which was not prescriptive enough to be useful for interchange. It ended up more as a kit of optional parts.
(DNG and NEF are both based on TIFF/EP. DNG was Adobe's proposal to ISO to make TIFF/EP a more useful standard).
(Adobe also supplied PDF to ISO. It is now, I think, 3 ISO standards, and Adobe don't own it. I think ISO have also taken over XMP, as they presumably needed to for PDF purposes).
---------- Post added 30th Oct 2018 at 04:16 PM ----------
Originally posted by Not a Number Take a PEF file. Convert it to DNG using Adobe's converter. Put the DNG on the SD card in your Pentax camera. The camera won't recognize the DNG no matter what version you convert the DNG too.
Tells you something right there about the "universality" of DNG files.
I've haven't time to check, but here is my guess:
The DNG Converter puts XMP into the DNG to record what it has done.
Probably the camera simply can't handle the XMP. After all, it is not needed by the camera and doesn't put it in the DNG.
If that is the reason, I don't know why the camera can't ignore it.
There are other possibilities.
Perhaps Pentax cameras write using a subset of DNG, for example with the image data stored in a particular way. But the DNG Converter (legitimately according to the specification) happens to use a different structure.
In other words, there is no need for a camera to implement the full generality of DNG, because it never expects to encounter it.