To look at Madan Mahatta's photographs of Delhi's architecture, taken between the late '50s and the mid-'80s, is to have a new eye open up in your mind. Emerging into the city from the quiet of the gallery, you become suddenly attentive to the forms of buildings: the angle of a staircase, light falling into a courtyard and an unnoticed dome on a building you've passed a hundred times. To have seen Mahatta's magnificent black and white images is to have implanted in your mind the ability to look at a familiar outline and see it as something fresh and new. It is, in effect, to be able to travel back in time.

Mahatta's family started the famous Mahatta Photographic Studio in Connaught Place in 1948. He returned from studies in England in 1954 and started work here, photographing the buildings being created in Delhi by a new generation of architects: literally, the building of Indian modernity. Like Mahatta, several had returned from training abroad. Habib Rahman and Achyut Kanvinde had studied under Walter Gropius of the Bauhaus School at Harvard and MIT, while Joseph Allen Stein had worked with Richard Neutra, and was inspired by Frank Lloyd Wright and Eliel Saarinen.

The new modernist vocabulary — the boldly dramatic geometrical forms, rough stone and poured concrete that characterised Raj Rewal's Hall of Nations, J.K. Chowdhury's IIT Delhi or Kuldip Singh's NDMC headquarters — was in stark contrast to the existing architecture of British New Delhi. Mahatta's photographs may create the illusion that 'Delhi Modern' was the dominant style of its era, but in fact it contended with, and responded to, what was present. And what was present was embroiled in debate — architectural debates that arose out of our colonial past that are still not completely dead.

The monumental classicism of Lutyens' and Baker's Delhi nodded to pre-colonial Indian styles. Some have suggested that these nods were rather cursory, that Lutyens' chhajjas — overhanging cornices along the side of a building, or over a door or window, and chhatris, decorative pavilions placed on a roof — were not based on existing Indian models, but instead reinterpreted them in an abstract, classicised idiom. By avoiding both the 'Hindu' and 'Moghul' elements of the colonial Indo-Saracenic style and modelling the roof of the Viceroy's House on the dome of the Sanchi Stupa, Lutyens thought he had gained neutral ground — Buddhism had no adherents in Victorian India. But, historian Thomas Metcalf argues this lack of connection to the present was precisely what made Lutyens' architecture a dead-end: "Confined within the classical traditions of European imperialism, it led, inevitably, nowhere."

Whatever the hopes of an anti-colonial historiography, official architecture in Delhi in the '50s and '60s had not emerged from Lutyens' shadow. The central dome of the Supreme Court (1958) was a simplified version of Rashtrapati Bhavan, and the major CPWD buildings built between 1955 and 1965 — Krishi Bhavan, Udyog Bhavan, Rail Bhavan — all had simplified domes, chhajjas and chhattris, grafted into classical style buildings.

The new modernists found them ridiculous: "Rahman and Stein made jokes about the new Supreme Court building coming up," writes photographer Ram Rahman (who is curator of the Mahatta show and the son of Habib Rahman). But for Lutyens acolytes like contemporary British curator Paul Waite, these structures were evidence that the wish to graft together Eastern and Western forms to create an indigenous architecture for India remained even after independence. For Waite, it is the coming of International Modernism that is cause for lament: "It did not matter if Le Corbusier was designing in Chandigarh, Paris or Morocco – it would be cement, high rise and without reference to any previous architectural traditions of the country. Architecture had to be the same the world over."

Ram Rahman believes exactly the opposite. For him, "What this generation of architects did was to develop a vocabulary of modernist practice suited to Indian conditions and connected to the ethos of the time". Stein, he reminds us, has spoken of how the spirit of Gandhi, still prevalent in the '50s, "meshed perfectly with the 'less-is-more' slogan of Modernism".

So is there really a 'Delhi Modern'? Do the cement and ceramic jalis of Stein's Lodi Estate or Rahman's Rabindra Bhavan make them 'indigenous'? Is indigeneity necessary? The debate is a fascinating one, and potentially endless. One way to resolve what one thinks is to begin to look more carefully at the buildings that surround us. Looking at Mahatta's image of the Shri Ram Centre, halfway through construction, it is impossible not to think of it as a spaceship that has recently landed, barely avoiding the elegant arcades of Connaught Place. And yet it is impossible to conceive of the Mandi House area today without the Shri Ram Centre. The alienating quality in the photograph has been erased by time and familiarity; even its once-harsh exterior seems softened by the presence of the little café.

Perhaps, despite all its conceits, any architecture is eventually dwarfed by those who use it. As it should be.