Canadian organizations. cole 
MO! 
Replies to the question: "For what uses is image quality most important?" ven 
covered every use of aerial photographs . There was a fairly strong opinion that i on 
improved image quality does give greater plotting accuracy, also that it is part- re ^ 
icularly necessary in forestry. 
Prir 
In-Flight Factors Affecting Image Quality 
Most replies indicated that in-flight quality is inferior to laboratory test results, ^ u1:( 
sometimes very decidedly so. However, one reply pointed out that details smaller 
than the resolution limit often appear in aerial photographs, and another considered use 
that modern high-speed shutters effectively stop vibration or forward movement. 
Son- 
Atmospheric haze is apparently not a universal limitation but in tropical areas does strc 
cause a great deal of trouble. Several replies indicated the need for a means of a m 
specifying haze. Q er 
Opinion is still sharply divided on the use of a window, but no evidence has been g tei 
quoted on either side. No one makes allowances for temperature or pressure changes 
in flight. Litt 
repc 
Several replies stated interest in stabilized mounts, but only the Netherlands report- t ^ ie< 
ed one in non-military use, this being experimental, so that its value in improving P r ° ( 
image quality is not yet known. No experiments proving the value of improved anti- 
vibration mountings were quoted. 
Ima 
Emulsions 
Most users are satisfied with present panchromatic emulsions, though more speed an ^ 
with less grain would naturally be welcomed. Ger 
pro] 
The use of infra-red emulsions appears to be slowly increasing, but their consump- sa -j- ; 
tion probably accounts for only a few per cent of the whole. They continue to be re fr 
applied for special purposes, such as mapping tide-lines and studying plant disease, 
and also for topographic survey under difficult conditions, e.g. in rain-forest and ^- nte 
tropical areas, where the increased contrast is useful when heavy haze is present. are 
Color film is being applied to greater extent, and its use appears to be growing at 
a faster rate than infra-red, though figures of consumption cannot be quoted. Special ^ n< 
studies and applications of color film were specifically mentioned by Austria, U.S. thal 
Coast and Geodetic Survey, Finland, Japan, the Netherlands and Switzerland. c 
The Swiss Topographic Service reports experiments with reversal color film, aimed at: in * 
1. Optimising filter and processing conditions for their own apparatus. A m 
2. Investigating the equipment and installation needs for proceeding via hen 
intermediate negatives to contact prints or enlargements on color paper 
or as transparencies . p e \ 
The successful outcome of these experiments made in conjunction with a commercial 
color processing laboratory, means that the Topographic Service should be able 
to supply color photographs for identification and interpretation in the near future. mac 
con 
Switzerland also reports successful commercial processing of single-shot 9x9