5.8 Japan: There is no new report from Japan to add to the Interim 
1974 Report of the Working Group. It is known that studies are 
continuing and standards are being developed. For further details, 
see 1974 Working Group Report. (also Ref. 48) 
5,9 United States of America: 
5.9.1 Standards: 
5.9.1.1 The American MTF Film Standard, ANS PH 2.39 is now ready 
for publication. The Forward, which is not a part of the proposed 
standard, draws attention to the fact that "one of the advantages 
of the modulation transfer system .... is cascading .... although 0 
such cascading would be useful and desirable in systems which in- 
clude photographic components, this standard does not claim that 
the Standard Photographic Modulation Transfer Function will neces- 
sarily give a representative system response when it is cascaded 
with other components of the system. Factors beyond the scope of 
this standard have to be included when precise predictions of 
the density of fine details in photographic reproduction are to 
be derived by cascading ..." The user of this standard is further 
reminded that photographic MIF is a measure of the apparent 
scattering of light within an unprocessed emulsion and not a measure 
of transmittance of the processed image. The gradient of the density- 
log exposure curve provides a very approximate factor relating the 
modulation associated with the light scattered within the unprocessed 
emulsion. Nelson's paper 9 gives a more exact relationship. 
5.9.1.2 The proposed American National Standard for "Optical Transfer 
Function, Measurement and Reporting" PH 3.57 is in the third draft 
form now including all sections. It defines OTF and related concepts, 
describing basic principles of OTF measurement methods, with selected 
examples discussed in detail and specifying the parameters connected 
with OTF testing. Common sources of error are briefly discussed. 
All known methods are presented. Because of the all-encompassing 
scope, it may be some time before agreement is obtained and the 
document is published. 
= 
5.9.2 U. S. National Bureau of Standard 
5.9.2.1 Microdensity: The problems of microdensitometry as caused 
by partial coherence and flare light have been considered by Swing 
and Grimes?0 Grimes5l1 proposes a Linear Microdensitometer where 
the sample is illuminated by a slit focused on a sample by a high- 
quality condenser, baffles between the condenser and the slit acting 
to control stray light. Approximately all of the light transmitted 
through the sample is collected by an optical element. The system 
has a number of advantages: