the performance of optical and electro-optical 
imaging systems and the relationships between 
image quality and image geometry. In general, 
OTF/MTF measurement techniques are now 
utilized by most major optical laboratories for 
lens testing and their validity for the prediction 
and measurement of the camera system (lens — 
film — image motion) performance has been 
established. 
Presented Paper 
Author: Dr. O. A. Gerasimova (U.S.S.R.) 
Title: The Determination of Modulation 
Transfer Functions of Airsystems 
at ZNIIGAIK PP 1/13 
Dr. Gerasimova told that at ZNIIGAiK there are 
two precise optical bench systems EOS-1 and 
EOS-2 for determining of MTF's. The accuracy of 
EOS-2 is X 296 and the spatial frequency range 
is 7.5—120 cycles/mm. She also proposed an 
approximation formula for MTF's based on 400 
MTF determinations. The EGA method will be 
replaced by some method using Fourier-spectra. 
Film threshould contrast curves are based on 
Fevensky-target measurements. 
Panel Discussion 
Topic: Testing of Lenses and Photographic 
Systems 
Moderator: Mrs. C. Norton (U.S.A.) 
Panelists: Dr. M. Gerencsér (Hungary) 
Dr. K. J. Rosenbruch (F.R.G.) 
Dr. E. P. Welander (Sweden) 
Dr. R. Welch (U.S.A.) 
Dr. Welander stated that OTF/MTF procedures 
are now well established and that the Section 6 
should be updated with tolerance, a task for 
a Working Group for the next period. Special 
attention should be given to wide angle cameras 
including the frame. 
Dr. Rosenbruch showed results of MTF measure- 
ments carried out of two complete reseau 
cameras with four measuring methods (Mr. J. 
Hakkarainen of Finland, Mr. W. G. Martin of 
U.S.A. and two different methods at PTB, F.R.G.). 
The first mentioned was photographic and the 
other three were photo-electric methods. The 
results of the one camera showed very good 
agreement, but the results with the other camera 
by the first method differed from the results by 
the other methods, because in the first method 
the camera frame plane was used as reference 
plane. In the latter methods this was the best 
focal plane. Dr. Rosenbruch pointed out that the 
reference plane can have a great influence on 
OTF measurements. Also the phase shift can 
have great importance when using some lenses, 
which should be taken into account especially 
in accurate distortion measurements, where the 
target used has influence on results. 
Finally Dr. Gerencsér made a few comments on 
the use of the EGA method for testing photo- 
grammetric systems. 
88 
Friday July 16, 1976, from 15.45 to 17.15 
Session 6 of Commission | 
Topic: Underwater Photography 
Chairman: Mr. G. McNeil (U.S.A) 
Invited Paper 
Author: Mr. G. NcNeil (U.S.A) 
Title: Determination of Limiting Reso- 
lution of Underwater Lens Owing to 
Change in Back Focal Distance 
Caused by Change in Water Refrac- 
tive Index IP 1/107 
Having presented parts of his Invited Paper, 
Mr. McNeil proposed an Underwater Photography 
Working Group under Commission | with close 
cooperation with Commission V. 
Panel Discussion 
Topic: Underwater Photography 
Moderator: Mr. G. McNeil (U.S.A.) 
Panelists: Mr. V. Seifert (U.S.A.) 
Dr. K. Torlegard (Sweden) 
Mr. D. Rebikoff (U.S.A.) 
Mr. Seifert referred to his State-of-the-Art” 
Report to the Commission | Symposium in 
Stockholm 1974. Developments have been made 
of camera systems and calibration techniques 
as well as of the knowledge and understanding 
of the significance of underwater photography. 
Dr. Torlegard discussed results obtained by 
himself and Mr. T. Lundálv (Sweden) concerning 
marine biology. A simple calculator-assisted 
mini-comparator has been developed to be used 
by the biologist for evaluation of stereo pictures 
over selected shallow sea areas. 
Mr. Rebikoff gave his Presented Paper, "1976 
Report on Underwater Photogrammetric Survey 
of Man Made Structures Located Underwater, 
Such as Oil and Gas Pipelines" (PP //25). He 
also demonstrated two underwater camera sys- 
tems with 250 and 1500 frame cartridges for 
format 24x 36 mm. Due to the low "altitude" 
possible major efforts have to be made to develop 
complete computer-supported automated evalu- 
ation systems considering the large amount of 
pictures that are produced. He also believed 
that many data program systems developed for 
aerial photography evaluation could be used 
with limited alterations. 
In the discussion Mr. Seifert urged people from 
other nations to join the I.S.P. work on under- 
water photography. Upon a question from Mrs. 
C. Norton (U.S.A.) on the scope of underwater 
photography, Mr. McNeil answered that the 
most important subject now was to get under- 
water photography established in the photo- 
grammetric world. Dr. Torlegárd, being a member 
of the Commission V Resolutions Committee, 
asked for resolution proposals in this matter. 
Monday, July 19, 1976, from 14.00 to 15.30 
Session 7 of Commission! 
Topic: Navigation and Flight Systems — 
Aerial Photography Instrumentation 
Chairman: Mr. F. Corten (Netherlands) 
Ww