Thank you for your interesting replies
!
Yes, I guess the topic is a tough one, since only the fewest of us have proven future-telling skills. From what I read from your replies, there appear to be 2 states-of-the-art right now:
1) Always copying the files to newest harddisks (or SSDs or similar devices) in multiple copies and storing them at different locations.
2) Printing the best images and rely on the longevity of the prints.
I guess the printing method would demand multiple copies of prints as well (not thinking about sold artwork now, but also private snapshot of undefinable emotional value). It would have the great benefit of not needing whatever-kind-of device in the future to read the "data". But it may be less than optimal if one really wanted to have backups of tens of thousands of files.
Thinking about it, an analog medium most probably actually is one of the more secure options. I'm thinking about governments that store documents etc. on microfilm in nuclear-war-proof bunkers. The beauty of this method is that microfilm could easily be accessed even in the far future. You just need some way to magnify, and that shouldn't be too hard to "re-invent", if necessary.
So, why not having a service that would print your RAW image onto a new kind of transparency film at let's say medium format size (for resolution's sake). Naively I would think that it cannot be impossible to create a future film material that could even have EXIF data embedded (maybe as micro text information on the side or so).
If there were a service that would write your digital image-date losslessly onto film, it could be easily and properly stored and recovered in the future.
Provided that in 200 years anyone would actually still have some interest in those files...
Thanks for the discussion so far