What kind of lenses with a "slightly different diffraction behaviour" were used in "large format photography in the 1980s"?

Question

Referring to an interview with a lens expert (Krolop&Gerst Objektivreihe 17/32), discussing diffraction limits.

"Es gibt ein paar Spezialobjektive die haben ein bisschen anderes Beugungsverhalten, aber da möcht ich echt nicht drauf eingehen, also dass ist Grossformatfotografie aus den achtziger Jahren"

"There are a few special lenses which have a slightly different diffraction behaviour, but I do not want to go further into this, since that is specific to large format photography from the 1980s."

What is the expert referring to here?

Answer 1

Apodizations filters in large format lenses were very popular in the 1980s. The baffles in such lenses can significantly affect the diffraction characteristics of such lenses.

Although lenses such as the Rodenstock Imagon had been around since the late 1920s, they had a resurgence when several 35mm camera makers introduced lenses for 135 format cameras that used similar baffles or screens to soften bokeh in the mid to late 1970s and 1980s.

_{Rodenstock Imagon "sink strainers"}

_{Fujinon 85mm f/4 SF (Soft focus)}

This Soft Focus "fad" peaked in the 1980s and lasted long enough for Canon to introduce the EF 135mm f/2.8 SF ('Soft Focus') in 1987 as one of their first EF lenses for the newly introduced EOS system.

_{Canon EF 135mm f/2.8 Soft Focus}

There are also several DIY 'tricks' to get the look of a soft focus lens.

While the only person who can say for sure what they had in mind is the person who wrote that statement, that would be my guess.