As an example, let's say that you are outdoors. Your camera has a Busch Rapid Aplanat lens, circa 1904.
What would you do with the lens to control scene contrast? Say on a sunny day, or a cloudy day.
Replace it with a different one. I'm not sure I understand the intent of the question---we all agree that a lower-contrast lens is going to lose information, in the form of microcontrast distinctions, that can't then be "resurrected" in the darkroom, don't we?
San Diego, CA, USA
The lady of the house has to be a pretty swell sort of person to put up with the annoyance of a photographer.
-The Little Technical Library, _Developing, Printing, And Enlarging_