A 
B 
C 
\_ . / 
t _. r p 
H 
Figure 18-1. Diagram of Video Recording Equipment. 
NOTE: A) TV camera, B) Photo tube, C) Wild M-5 microscope, D) wide-angle 
attachment, E) metal light shield with deep red glass bottom, F) container with 
test organisms, G) 800 nm interference filter, H) metal diaphram, I) clear glass, 
J) dark field stage with halogen light. Components E-H are shown separated 
from each other for graphic clarity. 
18-1). Video images were obtained using a Cohu 4400 television camera 
attached to the M-5 microscope body. The field of view recorded was 10x10 
mm. Optimum image contrast was obtained using a halogen light source with 
dark field optics at 8.5 volts (Figure 18-1). 
Spectroradiometer (ISCO-SR) readings indicate light transmitted through 
the stage filters was as low as 680 nm. Peak transmission occurred between 
810-840 nm. With the exception of light experiments, nauplii were moved 
directly from constant light temperature boxes to the microscope stage. Room 
lights were extinguished and, following a two-minute acclimation period, larvae 
were taped for 3-5 minute intervals using filtered substage illumination. 
Swimming parameters reported were determined by analysis of 30-60 second 
portions of these tapes; results are pooled from replicate samples. 
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