Section 80. Minimum resolution

A minimum resolution of 90 lines per millimeter shall be obtained regardless of reduction ratio used or the type of camera used and the 4.0 pattern shall be resolved for 16mm microfilm and the 6.3 pattern for 35mm microfilm. This shall be determined by the line count and direction method using the National Bureau of Standards Standard Reference Material 1010a (ANSI and ISO Test Chart No. 2) (or equivalent) for planetary cameras and the AIIM MS-113 Test Chart (or equivalent) for rotary cameras. No other test charts shall be used unless approved by the LVA. The test charts are composed of two groups of five parallel line pairs, the line pairs in the two groups being oriented perpendicular to one another, and each pattern is numbered and progressively reduced. Five vertical and five horizontal line pairs shall be clearly defined in both directions. The resolution test chart shall be photographed at the beginning and at the end of each reel of camera microfilm at least three times in succession.

NOTE: Resolution of duplicates should generally be only one pattern lower than the original from which the duplicate was reproduced. Pattern resolved times the reduction ratio equals lines per millimeter.

Resolution requirements for procedural microfilm recording. A minimum resolution of 120 lines per millimeter shall be obtained regardless of reduction ratio used or the type of camera used and the 5.0 pattern must be resolved for 16mm microfilm or the 3.2 pattern for 16mm microfilm being generated by the same office using digital imaging as a recording process. This shall be determined by the line count and direction method using the National Bureau of Standards Standard Reference Material 1010a (ANSI and ISO Test Chart No. 2) for planetary cameras and the AIIM MS-113 Test Chart for rotary cameras. No other test charts shall be used unless approved by the LVA. The test charts are composed of two groups of five parallel line pairs, the line pairs in the two groups being oriented perpendicular to one another, and each pattern is numbered and progressively reduced. Five vertical and five horizontal line pairs shall be clearly defined in both directions. The resolution test chart shall be photographed at the beginning and at the end of each reel of camera microfilm at least three times in succession.

NOTE: Resolution of duplicates should generally be only one pattern lower than the original from which the duplicate was reproduced. Pattern resolved times the reduction ratio equals lines per millimeter.

Historical Notes

Derived from VR440-01-137.1 § 5.4, eff. July 9, 1986; amended, Volume 07, Issue 24, eff. October 1, 1991; Volume 17, Issue 14, eff. May 1, 2001.

Statutory Authority

§§ 42.1-8 and 42.1-82 of the Code of Virginia.