Indeed all one can usefully achieve by dodging is 
to shade the background against which the fine detail 
lies; the sensational effect referred to is then 
obtained by giving extra emphasis to the fine detail 
recovered, by increasing the printing contrast. Furrows 
and surface patterns in the open fields then leap into 
view. It remains that when one departs from the open 
fields to those areas of particular interest where trees 
or man-made objects prevail, one frequently finds the 
entire negative density range taken up between the 
shadows and highlights of adjacent fine details. Dodging 
here has no effect whatever. Furthermore where dodging 
has been undertaken, the medium or contrasty grades which 
will have been used to emphasise the detail in the open 
fields will give rise to the higher percentage losses 
which are listed against these grades in Table I. Over 
and above this there will be the loss of detail in "edge 
effect" which occurs on dodged prints wherever there is 
a sudden large change of density between adjacent large 
fields of detail, for example, where open fields give 
rise to forest. 
In these circumstances although one can recover much 
negative detail by dodging or masking such as otherwise 
might fail to print, there still remains almost as much 
again that is lost. Further, in these paragraphs one is 
not considering the degradation of resolution, so that in 
the context of these paragraphs the word "recovery" 
simply implies the passage from a zone of no resolution 
at all into a zone of some resolution. The next para 
graphs will deal with the important question of resolution 
degradation. 
3.2. Resolution degradation in printing 
The writer must now describe some tests with an air 
negative exposed at a scale of 1/6000 over a resolution 
test object with 0.33 log brightness difference between 
the lines and spaces. The test object was exposed on 
fine-grain film of a type normally used; and developed 
to a gamma of 1.5* The target lay on axis of a Wild RC5 
6" Aviogon camera. From the test negative contact prints 
on bromide paper and glass lantern plates were prepared 
by various means; some in the Cintel Electronic Printer 
and some by using a distant point light source; great 
care was taken to achieve perfect contact. The resolu 
tion of the negative and contact prints was observed 
through a good quality microscope at a variety of different 
viewing magnifications and the results are shown in 
figure 2. There was a loss of 38$ between the resolution 
of the negative and the dispositive, and 54$ between the 
negative and the paper prints. These results have been 
confirmed by BergvO. The loss is due to the limitations