"I was associated with him for nearly four decades... a fruitful and friendly relationship. He was an institution to me. I learnt a lot and it helped me later on in my career," the 80-year-old Roy told IANS in an interview on the eve of Ray's 92nd birth anniversary.
Roy, who watched the ace moviemaker weave magic on celluloid during his years as a technician (handling trolleys and equipment) for his films starting with Pather Panchali, began working as a full-fledged cinematographer during the making of the 1961 Teen Kanya.
With Ray's former cinematographer Subrata Mitra developing an eye problem, the film maestro asked Roy to step in.
"Ray made the transition easy... he was extremely encouraging... plus he had vast knowledge, both theoretical and practical, about camera work. I had no problems in adjusting as I had already seen him at work. His directions, instructions were crystal clear," Roy reminisces.
Roy's repertoire includes 21 of Ray's films including Golden Bear winning movie Ashani Sanket (1973), besides Aranyer Din Ratri(1969), Sonar Kella, Joybaba Felunath, Shatranj Ke Khiladi, Seemabaddha and the documentary Sikkim.
Roy went on to work with giants like Tapan Sinha, Tarun Mazundar, Buddhadeb Dasgupta and MS Sathyu. He reveals that Ray used to have numerous sittings with the cast and crew together as well as individually to take them "step-by-step" through the shooting process.
"We were treated like a family member. There were no issues of superiority or inferiority. It was very uncommon... his way of dealing with the entire crew... he took care of us," divulges Roy.
According to Roy, Ray's "meticulous" manner of shooting was a result of his "organisational skills".
"The whole shot, from the set decorations to the dialogue delivery to lighting, was in his head. He used to scribble additional details besides the dialogues in his script book. There was nothing that he had not thought of," Roy explained.
However, outdoor shoots like the ones in Sonar Kella in Rajasthan's deserts and forts, were fraught with weather-related and equipment-associated issues. Ray remained "unperturbed and would come up with ways to get around the problem".
"There was no outdoor shoot that we couldn't complete. Everything was achieved, thanks to his patience and troubleshooting methodology," Roy said.
Despite Ray's organised approach, his avant-garde filmmaking endeared him to Roy and international audiences.
"He was not rigid. He experimented a lot... in every film there was something new to learn. That was his nature... to push boundaries and he achieved fantastic results we couldn't have even thought of," Roy elaborated.
Recounting one such "experiment", Roy said: "For example, in the film Abhijaan (1962), there was a shot where a road lit with headlights of a car, in darkness, is shown. Ray told me he wanted it like this and said see if you can do something about it. We found out that a 24V light used in airports was available. We attached that to the car and shot the scene.
"It is very easy to shoot such sequences today with digital effects, but in those days it was difficult".
As a mentor, he used to ask Roy and his fellow technicians to "study the great artists and painters of the world, to imbibe a sense of black-and-white and colour tones from their work into the art of filmmaking".
Through the years that Roy worked with him, the multi-talented Ray evolved as a filmmaker.
"He used to look back on the films that didn't do well financially, and noted what he should have done. He critiqued his own work," Roy told IANS.