I remember reading about this back in one of the mainstream photo magazines in the 1960s. At the time, Zeiss was taking a lot of flack for making slow lenses (they made very good lenses, but for lots of uses, their lenses were too slow for the new, gritty, world of 35mm photojournalism). This lens was a major counter-thrust in that war. The lens consisted of an enlarger condenser element, cobbled into a mount, with an aperture and so forth. Zeiss was saying very loudly that anybody can make a fast lens if you don’t care how good it is.
See Petapixel article for more detail.