There are a lot of portraits of life in the city these days with the likes of the Fab Collective documenting Liverpool in the 21st Century and our own Picture This segment curated by Sam Bytheway every Friday.

But digital photography and the rise of home tech – laptops, iPhones, Facebook, Flickr – has democratised photography, or certainly popularised it, in a way that was not the case back in the 70s.

Quality images in the public arena from those days tend to reside in the archives of regional or local newspapers and every now and then get an airing at a local museum and a limited print run. They are, almost universally, fascinating portraits of bygone times in Liverpool

Recent exhibitions at the lamented Conservation Centre by Stephen Shakeshaft and Francesco Mellina were particularly good and now the Walker is displaying a number of images by Paul Trevor that haven’t seen the light of day since the mid 70s, titled Like You’ve Never Been Away.

Trevor spent six months living in a tower block in 1975, documenting inner-city deprivation around Everton, Lodge Lane and Toxteth for a photography project and building up an incredible document of the period.

The images show just how extraordinarily different life in urban Liverpool was in those days. There’s a Life On Mars-style nostalgia to the images in some respect – the hair, the clothes, the cars – but it’s a scarcely believable record of the deprivation and poverty, almost the squalor of the time.

The cramped terraces of Handel and Mozart Street near Lodge Lane and the blasted landscapes of the area speak volumes of how much things have changed. The images of filthy children in threadbare clothes playing among the ruins of Victorian terraces and dereliction, coupled with smog and dirt, recall not only the blitz, but an almost Dickensian time.

Yet the overriding impression is one of the simple pleasures of working-class life: streets of people talking to one another; children playing together in dens and back alleys; beaming families in their small houses.

Trevor’s images of children are particularly lovely – and inconceivable these days. A young lad lounging on a Chopper; a young girl having her photo taken in a new dress outside a church; an iconic image of a child holding up a picture frame.

Perhaps best of all is a shot of a Dad holding up a young lad in the path of a jet of water, sprayed from a hose in a water fight. It’s really delightful. At the other end of the scale are shots of Haigh Street and The Tarmac on Salisbury Street looking almost nightmarish.

Also on display is a short from the BBC’s Inside Out that shows Trevor barely able to recognise Liverpool, astonished by how clean and tidy the same areas are. It shows just how much times have changed and highlights the fact that the mid 70s in working-class Liverpool could be dirty, dangerous and harsh.

On a card outside the exhibition is a message from a member of the public that praises the images but warns ‘sentimentality is for those who come and look’. Perhaps, but we should be very grateful that we can go and look.

Like You’ve Never Been Away
Walker Art Gallery
Until 25 September 2011

NB. This article was amended to correct the location of Handel Street and Mozart Street