For 30 years he documented the excesses of his era, with public nudity unapologetically a favourite subject. But somehow such exposure seemed absurd, ironic and even poetic when Ellis discovered a seemingly hapless subject nude - in public.
His was a gently satiric eye and, walking along the carefully sequenced pictures at Ellis's retrospective at the National Gallery of Victoria, you may wonder, in this post-Henson era, what all the fuss about nudity is about. And how much Australia has changed in 30 years.
One particular picture is telling. Ellis photographed a section of the crowd at a Calder Park pop festival in 1977. Most are women and oblivious to Ellis. Even the confident young woman clearly the focus of his attention remains dreamily absorbed by the event. Wearing only a crucifix, a necklace of silver stars and a leather bondage collar, the topless woman is barely given a glance by her fellow revellers.
Ellis also recorded the culture of sport in an era when money and huge audiences did not confer unwanted responsibilities as role models on athletes. With concise composition and wry humour, he photographed the prelude to the 1974 Australian rules grand final as Richmond hard man Robert McGhie sits on the MCG boundary, adjusting his shoes while dragging on a freshly lit cigarette.
I never had the chance to ask Ellis whether he regarded himself as a photojournalist. I suspect he would have shied away from anything that labelled his photography. One thing is clear: the gentle persistence of his vision still enriches us today.
There is another revealing picture in the catalogue that accompanies the show. Bob Bourne's 1974 portrait catches a joyful Ellis, all long flowing hair and moustache, raising his battered black Pentax SLR. The lightness with which he holds his camera is palpable.
Ellis would transfer that delicate touch to almost every photograph - from a young woman revealing almost all as she propels herself downwards into a Ferrari in Toorak in 1976 - to an impossibly well groomed Andrew Peacock lunching with his then wife Susan in 1969.
Ellis may not have considered himself a photojournalist but his extensive archive offers intimate access to an Australia tantalisingly now just out of reach.