Rivers in New Mexico on October 30, 1975. The camera was mounted 
on a door mount platform, described by Meyer 1973, on a Cessna 182 
aircraft. The camera light meter with filter in place was read and 
set at 1/2 f stop overexposure. The aircraft was operated at 100 mph 
and at 2000 feet above datum due to the 800 foot canyon in the lower 
portion of Red River. 
The Nikon F2 camera was again used with Wratten 3 filter and Ektachrome 
X ASA64 film to photograph the same portions of Red and Rio Grande 
Rivers on May 5, 1977. The camera was mounted in a Cessna 182 | 
aircraft equipped with a camera floor mount designed by W.E. Woodcock, 
Miles City, Montana. The camera light meter was read with Wratten 3 
filter in place and adjusted for a 2 f stop overexposure to achieve | 
water penetration with Ektachrome X film as described by Lockwood, 
et al, 1974. 
A camera shutter speed of 500 was used with both color infrared and 
Ektachrome X film. The camera lens was set on infinity and taped in 
place with masking tape to prevent lens movement during flight. 
The 35mm format used in all tests required enlargement with a 
Vantage II microfilm reader with F series lens for interpretation of 
stream habitat conditions. 
A stream habitat inventory was accomplished by first ground truthing 
the area to be photographed and measuring the linear distance between 
two prominent land marks. Stream shade, upper stream bank condition, 
stream bank stability, stream channel stability and percent stream 
bottom silt were rated and the ratings for each category summed for 
an overall numerical and adjective stream habitat rating. 
Aerial flights were not made if cloud cover exceeded 15 percent. 
Flights were scheduled from 11 a.m. to 1 p.m. for maximum sun 
azimuth to reduce shadow as much as possible. The maximum sun azimuth 
and "peak of green" for vegetation occurs between June l and August 30 
in the temperate zone of the United States. It was not possible for 
aerial photography to be completed during this period of time.  There- 
fore, dates as close as possible to this period in May and October 
were selected. 
Results 
Kodak color infrared film overexposed 1/2 f stop provides water pene- 
tration in clear streams. Figure 1. 
Ektachrome X film with a Wratten 3 filter and 2 f stop overexposure 
gives good water penetration in large streams, Rio Grande River, and 
medium size streams, Red River. Figure 2. 
The aircraft door camera mount and the aircraft floor camera mount were 
both satisfactory for continuous strip photography of streams.