SIMPLIFIED PROCEDURES FOR EVALUATING THE IMAGE QUALITY OF OBJECTIVE LENSES FOR NIGHT VISION DEVICES - LAW ENFORCEMENT STANDARDS PROGRAM

• NCJ Number: 13388
• Author(s): C GROVER
• Date Published: 1974
• Length: 31 pages
• Sponsoring Agency: US Dept of Justice; US Dept of Justice NIJ Pub
• Corporate Author: US Dept of Justice
• Sale Source: Superintendent of Documents, GPO; National Institute of Justice/
• Language: English
• Country: United States of America
• Note: NATIONAL INSTITUTE OF LAW ENFORCEMENT AND CRIMINAL JUSTICE STANDARD PREPARED BY NATIONAL BUREAU STANDARDS

Annotation

TWO TEST METHODS ARE DESCRIBED FOR DETERMINING THE SUITABILITY OF A PHOTOGRAPHIC LENS FOR USE WITH A NIGHT VISION DEVICE.

Abstract

USERS OF NIGHT VISION DEVICES (NVD) IN LAW ENFORCEMENT WORK MAY AT SOME TIME DESIRE TO MODIFY THE CAPABILITY OF THEIR NVD BY EMPLOYING A PHOTOGRAPHIC LENS. THE METHODS DESCRIBED ARE THE LOW CONTRAST RESOLUTION TEST (LCRT) AND THE VARIABLE CONTRAST RESOLUTION TEST (VCRT). BOTH EVALUATE A PHOTOGRAPHIC LENS' LIMITING RESOLUTION AT A PARTICULAR CONTRAST LEVEL OR AS A FUNCTION OF CONTRAST. ALTHOUGH THE VCRT IS MORE COMPLEX AND PROVIDES BETTER OVERALL EVALUATION, BOTH PROCEDURES HAVE CORRELATED WELL WITH LENS RANKING DATA OBTAINED BY COMPLICATED MODULATION TRANSFER FUNCTION METHODS AND ARE RECOMMENDED AS SIMPLE CRITERION TESTS FOR LENS SUITABILITY. ILLUSTRATIVE GRAPHS AND PHOTOGRAPHS ARE PROVIDED. (SNI ABSTRACT)