[wiseman]

Why is it that the raw PEF file changes in some manor with each new Pentax camera (as I assume it does with the other camera makers)? When you purchase a new to market camera there will be a period of time before the various software makers update their product to handle the new proprietary raw file. If the differences exist due to improvements in image quality and/or file handling abilities that is all well.

This got me wondering, though, about the raw DNG format. I have read many threads on PF that suggest using DNG until your particular image processing software releases an update for your new model camera proprietary raw format. From this I assume that I could shoot in DNG with a new K-5 and use my existing software (which handles DNG from my K10D) to process the image. Is this truly the case? If so, it seems to me that the DNG format would be losing ground when compared to the ever evolving proprietary raw formats. I have seen no mention in the forum of DNG becoming inferior to other raw formats.

What am I not understanding correctly?

[Canada_Rockies]

DNG is Adobe's public format. Only Pentax allows you to shoot RAW in DNG among all the camera manufacturers. The major difference between DNG and PEF seems to be that DNG embeds the EXIF data in the RAW file. The only differences I have noticed in my photos is that the PEF file has some built in compression, and the DNG files do not - they are larger. Right now I am in a DNG phase, but I'm going to go back to PEF. My reason is rather odd: it's too hard to distinguish between RAW files that I have already processed with DxO (DNG saved) to those not processed by DxO. For my convenience having the PEF and DNG versions side by side lets me see what DxO has done for me. I can load both images side by side in LR 3 without having trouble distinguishing between them as to which is who.

[Miguel]

My semi-educated guess is that the major reason that the PEF file changes with each new camera release is because the spec of the file incorporates a specific camera model ID data field.

Software manufacturers have to incorporate this new model ID into their reference database(s), so this is the reason for a time delay.

One reason for having the camera save the file as a DNG is that you can bypass this incompatibility with existing "older" RAW conversion software and get results now. That's the short-term advantage to DNG.

So saving a K-5 file in DNG would allow you to immediately use ACR, Lightroom and others, without having to convert the file using the Pentax-supplied software (which I used once for two minutes six years ago).

Long-term, who knows, there some controversy about DNG vs. proprietary RAW formats.

M

[deejjjaaaa]

Only Pentax allows you to shoot RAW in DNG among all the camera manufacturers.

ouch - you somehow managed to forget Leica, Samsung, Ricoh...

[Canada_Rockies]

ouch - you somehow managed to forget Leica, Samsung, Ricoh...

Sorry! I done screwed up! Samsung allows DNG but not PEF! I got it backwards.
Mea Culpa, mea maxima culpa.

[Parallax]

In models prior to the K7, the DNG files were not compressed so there was a file size advantage fro PEF. With the option to shoot a compressed DNG I know of no advantage to shooting PEF.

[wiseman]

Thanks for the replies.

I did not word my original post very well. I was looking for what (and why) is changing in the raw formats (eg. PEF, NEF, CRW, etc.) each time a new camera model is introduced. Miguel guessed that the new camera model ID is what is changing and that is probably correct.

But, I assume there must be more going on than just a new camera ID in the file. Doesn't it seem silly to render the file "unprocessable" with your current software over something like the camera model ID in the metadata of the PEF file?

I am probably over simplifiing things, but it seems that a PEF file should be readable by our software irregardless which Pentax camera produced the file. The DNG format is a standard which is not tweaked each time a manufacturer improves its next generation camera. So why does Pentax need to customize the PEF file for each camera? If the changes are to make the images better, shouldn't the DNG file then look worse in comparison?

[Parallax]

..............tware over something like the camera model ID in the metadata of the PEF file?

I am probably over simplifiing things, but it seems that a PEF file should be readable by our software irregardless which Pentax camera produced the file. The DNG format is a standard which is not tweaked each time a manufacturer improves its next generation camera. So why does Pentax need to customize the PEF file for each camera? If the changes are to make the images better, shouldn't the DNG file then look worse in comparison?

The changes being made are possibly ones that have no effect on the IQ; e.g. compression algorithm, or address of the jpg preview within the file, where the exif is located, etc.

[Miguel]

[deleted]

If the changes are to make the images better, shouldn't the DNG file then look worse in comparison?

Research how DNG files are different from straight RAW files. I believe DNG files are wrappers around RAW files and it's the platform-agnostic nature of the wrapper that makes it a valuable alternative. So any specific imaging improvements to the original RAW files are maintained in DNG conversion.

M

[jbinpg]

Camera manufacturers use their own formats to best incorporate any improvements or changes in successive camera models. There may come a time when the DNG format is no longer "wide" enough to incorporate such improvements. Unless the DNG format keeps pace with these changes, it will eventually be useless. Since DNG is an open format, it *should* be easy to keep it current. It all depends on how closely the individual camera manufacturers guard their own formats for competitive advantage. We have no way of knowing if Hoya passes along changes to the DNG standards body but I suspect they do since they offer DNGs as a file format.