Virginia Administrative Code
Title 17 - LIBRARIES AND CULTURAL RESOURCES
Agency 15 - LIBRARY BOARD
Chapter 20 - STANDARDS FOR MICROFILMING PUBLIC RECORDS
Part V - Microfilming Procedures
Section 17VAC15-20-80 - Minimum resolution

Universal Citation: 7 VA Admin Code 15-20-80
Current through Register Vol. 41, No. 3, September 23, 2024

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.

Statutory Authority

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

Disclaimer: These regulations may not be the most recent version. Virginia may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.