Matthew, honestly, have you ever really , truly, studied the photos in the 1960's era Model Airplane News under a magnifying glass??? What did you see besides a myriad of dots...?
The old eyeglass with about (pressumably ) 4X magnification. Main thing is it brings the pictures to life,,
More as if your looking at the object photograped than a picture. Good for the old pommy racing motorcycles too.
Onnce measued the exhaust stubs on a Griffon ( 35 3/4 in ( as is spinner dia . ! ) and drew a scale drawing for a griffon sea fury.
late at night when the eathers are silent . Unfortunately forgot id done it, and repeated the exercise some weeks later .
One Cowling line was the thickness of the ink line dierant. the rest identical, on laying the tracings over ea. other.
Took this to prove one can scle from photos , if enlarged and telescopic effect corrected ,after deriving vanising points from
parrallel edges.Total pain though.Takes some months of studying the pictures beforehand to analise the structure and method of constuction
underneath.
Deriving airfoils and dimensions from shots of uncovered stuctures in photos is childs play in comparison. You blow up the picture about 400 % . ( yes , it is all dotty ! )
and sharpen your pencil !
A lot of engineering three views and exploded drawings ( like those aircraft stuctural drgs ) in periodicals are considerably reduced from the size they were originally drawn at ,
Probably A-O, ( twice A1 size ). About six months after having ceased drafting , one becomes somewhat clear headed. It takes that long for all the information to stop going around inside the mind !
An Occupational Hazzard . !