California Code, Government Code - GOV § 27002.1

(a) The treasurer may, in lieu of entering in books an account of the receipt and expenditure of all money received or paid out by him or her as provided in Section 27002, photograph, microphotograph, photocopy, or enter into an electronic data-processing system that utilizes optical transmission and filing, all receipts for money received by him or her and all warrants paid out by him or her.

(b) Every reproduction described in subdivision (a) shall be deemed and considered an original, and a transcript, exemplification, or certified copy of any of those reproductions shall be deemed and considered a transcript, exemplification, or certified copy, as the case may be, of the original.

(c) All reproductions described in subdivision (a) shall be properly indexed and placed in convenient, accessible files. Each roll of microfilm shall be deemed and constitute a book, and shall be designated and numbered, and provision shall be made for preserving, examining, and using it.

A duplicate of each roll of microfilm shall be made and kept in a safe and separate place.