Cal. Gov't Code § 26205.5
At the request of the county recorder, the board of supervisors of any county may authorize the destruction of any or all of the filed papers or record books created by handwriting, typing on printed forms, by typewriting, or by photographic methods, in the recorder’s official custody, if all of the following conditions are complied with:
(d) A true copy of archival quality of the film, optical disk, or any other medium reproductions shall be kept in a safe and separate place for security purposes.
However, no page of any record, paper, or document shall be destroyed if any page cannot be reproduced on film with full legibility. Every unreproducible page shall be permanently preserved in a manner that will afford easy reference.
For the purposes of this section, every reproduction shall be deemed to be an original record and a transcript, exemplification, or certified copy of any reproduction shall be deemed to be a transcript, exemplification, or certified copy, as the case may be, of the original.