During the first meeting of the Underwater Photography Committee it was concluded that the initial action 
to be taken during 1970 was the preparation of state-of-the-art reports on cameras, films, lighting, 
bibliography, and systems. These reports were presented during the 1971 ASP/ACSM Convention and 
subsequently published in the September 1971 issue of PHOTOGRAMMETRIC ENGINEERING. 
The state-of-the-art reports were updated during 1971 on an international basis for presentation during the 
12th Congress of ISP. The session will also include a panel discussion covering: 
À. problems that remain and thoughts on how they might be solved, and 
2. current and potential areas of research. 
27. Meier, H.K. 
Germany (F.R.G.) 
AUTOMATIC EXPOSURE METERS FOR AERIAL CAMERAS 
Automatic exposure meters, which have almost become a standard feature even on amateur cameras, have been 
conspicuously absent in aerial cameras until Zeiss recently introduced the EMI-2. 
Before the ‘automatic’ of an exposure meter can function, however, it is necessary to measure the light. In aerial 
photography, the first step in that direction is to determine theoretically the luminous intensity of the object 
and then the gradation. Only then will the required exposure factors, mainly exposure time and f-stop, have 
been determined. In doing so, image motion must furthermore be taken into account. A prototype 
maxima-minima exposure meter that performs in this manner (the Zeiss EMP) was flight-tested but proved 
to be too complicated for aerial photography. 
The Zeiss EMI-2, however, is an integrating instrument that is simple in design and operation; its worth has 
been proven through numerical estimations and in flight tests. The application of the instrument is 
discussed. 
With the EMI-2, Zeiss is offering an automatic exposure meter for all of its aerial cameras which is now 
available in addition to the simpler EMI-1 exposure meter. 
28.  Perlado, J.P. 
Spain 
AN AERIAL INFRARED THERMOGRAPHY SURVEY 
OF THE CANARY ISLANDS 
This paper describes a thermographic coastal survey of the Canary isles as requested by the UNESCO 
sponsored 'Scientific Study on Water Resources in the Canary Islands'. Main purpose of the survey was to 
explore coastal discharges of fresh water into the ocean through detection of thermal differences. Additionally 
the survey was supposed to yield preliminary information on geothermal areas of Lanzarote. 
Flights were performed on May "71, using a DEI-Infrared Scanner with detectors ranged in the 4.5 - 5.5 
wavelength for coastal survey and 8.5-12 4 for geothermal areas. 
The interpretation of imagery yielded abundant thermal anomalies due to (1) marine currents and tidal 
phenomena, (2) man-made effluents, and (3) probable natural submarine springs. 
Only ten per cent of anomalies are deemed to belong to third category. The relatively poor amount of natural 
discharge points is hoped to fairly well related to hydrogeologic conditions of the islands and the generally 
exhaustive ground water pumping. 
Imagery concerning geothermal areas appeared to be uninterpretable due to daylight effects.