I see this question come up with some frequency on various discussion forums. What format should I use to future proof my digital images. The answers of course vary from JPEG, to DNG, to TIFF or PNG. Very rarely do I see someone who responds with don’t do anything, which is exactly what I recommend.
This may sound shocking, but let me explain. There are two broad aspects as to why I don’t recommend messing with your digital negatives now for future proofing reasons. On one hand, there’s the technological and technical side of digital storage and computers; on the other, there simply the time aspect.
Let me start with the time aspect. Doing anything that involves converting RAWs now is a waste of time for two reasons.
First, is that it’s simply not a foregone conclusion that the manufacturer RAW files will become unreadable. A lot of DNG proponents like to play up the fact that DNG is an open standard and the proprietary RAW formats aren’t. They argue that because of that a DNG can be expected to be readable at some arbitrary point in the future. While that’s true, it ignores the reality that by far the vast majority of manufacturer RAW processing implementations were written by reverse engineering the RAW files themselves and not by using some manufacturer provided library. So long as people still understand graphics processing and statistics, there will be people who can understand converting a Bayer pattern blob into a usable bitmap image.
Moreover, even if it does become necessary to convert to another RAW format at some point in the future, the realities of the progression of technology suggest that doing so at that time will be faster than doing so now.
The second aspect is relates to the realities of digital storage media and the progression of technology. It seems to me that many of the people talking about future proofing their RAWs, are really looking for the digital equivalent to being able to stick slides in an archival container in an archival vault and not think about them for 50 years.
The simple realities of digital storage are that the media degrades and the devices to read it become obsolete and disappear. Long-term digital storage is more about moving data to new media in a controlled way than leaving it alone in a vault somewhere to degrade into uselessness.
Also, it’s important not to forget the management of the physical media involved. Newer media has higher storage densities, meaning you need fewer disks or tapes to store the same amount of data. The counter point is that with more data in fewer containers the loss of a single container means losing more data. That said, if you can consolidate 4 disks or tapes of data into 1, you could keep 2 duplicate copies and still have fewer disks or tapes to keep track of while having more redundancy in the system.
Given the realities of progress, it’s not hard to envision a scenario where the files on an archived disk are still readable in current software, but the disk itself can no longer be read.
The final point I want to make is that simply future proofing the RAW files doesn’t future proof the rendering of the image. What I mean by this is that the conversion from RAW data to a usable image that we can see as intended is as much a product of the software used to convert the image, as it is the data in the file.
We’ve already seen such changes in rendering in software like Lightroom. The 2010 process introduced a much more advanced rendering engine, producing better fine detail with better noise reduction, and different controls. Files updated from the 2003 process to the 2010 process not only looked different, but in some cases, couldn’t even be made to reflect the output of the 2003 process.
If there is a concern that the image might change, then it’s not enough to simply be able to read a RAW file in the future, but as much concern has to be given to it being processed under the same engine in the same way as it was in the past.
Instead of worrying about future proofing RAW files, I find it’s much more important to worry about insuring that you have the files to work with in the future at all. This means worrying about backups and data integrity. Both of which are topics that warrant a post or more discussing.