D'Amico/Valentini touch the interesting subject of using yellow filters to improve contrast on B&W film, they illustrate this by including a rare with and without filter photo, the resulting effect is quite stunning.
Slightly off topic, but I did not remember ever seeing such a good example.
p.12
Aeronautica Nazionale Republiccana 1943-1945
A Photographic Analysis through Speculation and Research
Ferdinando D'Amico & Gabriele Valentini
Classic Publications, 2005
1-903223-29-6
Shameless plug for their work, but hey I have
Classic stock
