Two Men Sat In A Pub

[Mr G]

Two Men Sat in a pub, one says to the other, " wouldn't it be nice to use small filters on a mirror lens", the other says "I'm sure we could come up with something". They part company and set about solving their dilemma, the first man comes up with a system and takes it to Sigma, the Filtermatic is born, the second man comes up with a system and this monstrosity is born!



Any idea who made it? and any idea what IQ is like? It's labelled Sunagor can't find much info anywhere although google images shows identical lenses in Chinon and Lentar branding. Pictured for scale next to my AE-1.