Sinéad Morrissey's "many-angled … any-angled" poetry collection Parallax has won the Northern Irish poet the prestigious TS Eliot prize for the first time.

Opening with a definition of parallax as "apparent displacement, or difference in the apparent position, of an object, caused by actual change (or difference) of position of the point of observation", Belfast's first poet laureate's fifth collection explores the word from all angles, looking at what is caught, and lost, when a moment in time is fixed by a photograph, a map, a painting – or even a jigsaw.

In Home Birth, she writes of "the night your sister was born in the living-room … this black-haired, / tiny, yellow person who'd happened while you slept"; in The Doctors, she evokes the history of Soviet Russia, how "the camera's / inherent generosity of outlook" is countered "by scissors, / nail files, ink and sellotape".

With her image of David Niven on an escalator to heaven in 1946, and one of LS Lowry's studio after his death, Morrissey's Parallax beat collections from major names in poetry, including George Szirtes, Michael Symmons Roberts and Anne Carson to win the prestigious £15,000 award.

Parallax had lost out to Symmons Roberts's metaphysical collection Drysalter in the Forward prize last year.

Morrissey, who is currently reader in creative writing at the Seamus Heaney Centre in Belfast, was shortlisted for the TS Eliot prize on three previous occasions; her win puts her alongside former winners Paul Muldoon, Alice Oswald, Derek Walcott and Heaney.

The chair of judges, Ian Duhig, said he and his fellow judges, Imtiaz Dharker and Vicki Feaver, had been unanimous in choosing Morrissey's collection from among the 10 titles shortlisted.

"Politically, historically and personally ambitious, expressed in beautifully turned language, her book is as many-angled and any-angled as its title suggests," said Duhig, who is himself an award-winning poet.

In A Matter of Life and Death, Morrissey writes about the moment of going into labour as the Michael Powell and Emeric Pressburger romantic fantasy from the 1940s plays on television, going beyond childbirth to explore "the incomprehensible machinery of life and death"

In another poem she looks at the first ever jigsaw, given to "Royal children in 1766": "Staring and exclaiming, clicking together / … a continent – / Their own unlikely island on a slant / by its farthest edge, and in their trance ignore / what will no longer fit: Aortearoa, America".

"It is a meditation on this idea of parallax, looking at things from different angles. This speaks through the whole book," said Feaver.

The prize is run by the Poetry Book Society and supported by the TS Eliot estate and the investment firm Aurum.