We are currently in the process of a preservation project for a deceased US senator the media being “preserved” includes Film (16mm and 35mm) and video such as VHS Beta TypeC etc.
Upon review of the options with the library and research into archivist papers DVD-R was ruled out very strongly as real world testing showed even the best media deteriorated sharply at or before the 10year mark and many much earlier.
Direct to disk was considered but continuous maintenance and lack of reliable spin up after extended off periods ruled it out.
The video collection is being put to 2 simultaneous DvCam tapes with one in storage at a cold mountain facility and the other in the library for access. We projected a re visitation of the new tapes in 20 years with trepidation that they would be readable and we are placing a DvCam deck in storage as well in case there are not any anymore.
The film got duplicates and in a few cases a 3 strip separation the color prints are fairly well assured for 100+yrs and the seperations (3 B+W films one for each color) are projected to be viable for a millenia and are on the archivists short list of “permanent”
That’s a professionals look at a archival job.
I would transfer all of your family material onto 2 dv tapes each and keep the two copies in separate places.
D5 is a top end HD tape format which is 1080i or 1080p by 1920 with 4:2:2 color and low compression (2.5:1 or so) a deck is $70k or so 😉
-Rob-