CONTENTS 



page 



2 INTRODUCTION 



3 GENERAL DESCRIPTION OF CAMERA 



7 OPERATIONAL INFORMATION 



7 Selection of Subject Material and Field Coverage 



8 Camera Settings, Film, and Optics 



8 Field Illumination 



9 Bottom Contact and Weight-Strength Relationships Between 



Camera and Lowering Rope 



11 Maintenance and Care of Equipment 



12 Limitations 



12 APPLICATION OF THE CAMERA TO THE STUDY OF 



OCEAN-FLOOR ENVIRONMENTS 



12 CONCLUSIONS 



17 RECOMMENDATIONS 



17 REFERENCES 



ILLUSTRATIONS 



NEL Type III Deep-Sea Camera 

 Camera and power supply unit in camera case 

 Camera and power supply unit 

 Schematic diagram of electrical units assembly 

 Schematic diagram of circuits of NEL Type 111 Deep-Sea Camera 

 Diagram of field of photographic coverage 

 Optics for NEL Type III Deep-Sea Camera 



Plan view of a typical deck arrangement for lowering camera and indicating bottom contact 

 Underwater photographs of some typical sea-floor environments taken with 

 the NEL Type III Camera 



TABLES 



page table 

 10 1 Weight-strength relationships for lowering NEL Type 111 Oeep-Sea Camera 



INTRODUCTION 



The increasing use of photography in studies of ocean-floor environments created 

 the demand for a small, portable camera unit to replace the heavier, more cumbersome 

 underwater cameras previously developed at NEL.^ (See list of References at end of 

 report.) Field exploration with the heavier cameras, one of which weighed over 2000 

 pounds, required the use of a vessel equipped with a strong winch, booms, and a heavy 

 wire lowering rope. The lowering rope most widely used Is of 3-by-19 stranded wire, 

 3/16-inch in diameter, with a breaking strength of 3340 pounds. The NEL Type III 

 Deep-Sea Camera was designed for safe lowering on such a rope to a depth of 20,000 

 feet, and its over-all submerged weight in water is 125 pounds, which satisfies the 

 applicable safety and working load requirements. 



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