It’s quite an audacious project: 83 canvases of identical size, each portraying an individual looking at the viewer from the same chair with the same backdrop. If the artist were anyone other than David Hockney, it certainly would have bombed. As it is, while some portraits seem to capture the uniqueness of the sitter, they don’t all work as individual portraits, despite the bravura and confidence with which Hockney tackles the subject. There is a sameness about them that blurs the subject and one feels that looking closely they don’t all stand up to scrutiny.

The Royal Academy had a runaway hit with Hockney’s portrait of Yorkshire in the glorious technicolour that was his 2012 A Bigger Picture, and they are expecting a similar public response here, but there isn’t quite the same all-embracing warmth from the work that there was in the previous show.

82 Portraits and 1 Still Life (until 2 Oct) needs to be seen as a single entity to fully appreciate its strengths. Hockney crashed from the high of his huge 2012 success with personal tragedy that led to a creative hiatus, and he returned to his American home in Los Angeles. The first work shows his gallery assistant, head in hands, in what the artist described as something of a self-portrait. In the first few portraits Hockney is experimenting with a technique he hadn’t used for twenty years, acrylic paint, which dries unforgivingly quickly. In time though, he discovered a type of acrylic that could be treated more like oil paint. It was around this stage that he decided he had a series on his hands, but how it would end, even he couldn’t say.

Walking through the small Sackler gallery upstairs at the Royal Academy, one begins to see the flow of this narrative. The sitters are not celebrities, not of the conventional sort anyway. They are the movers and shakers of the international art scene, and in particular of LA’s art world. There are also portraits of old friends, dealers, his masseur, the guy who washes his car, his housekeeper and her daughters, very loving portraits of his extended family, in particular his brother, sister and sister-in-law. Other works are less successful, such as those of his friend Celia Birtwell and her grand-daughter. Celia was the model for an iconic work from the early Seventies, Mr and Mrs Clark and Percy, now hanging in the Tate. This exhibition would have been much more engaging if one had a short note on who the sitter was, rather than just their name, as these snippets of information add hugely to one’s understanding and appreciation of the work as a whole.

Sitters were invited on the understanding that the portrait would be completed in three days, so Hockney worked very quickly. He sketched in the subject in charcoal on the canvas and then blocked it in. His subjects were invited to wear what they liked, but the only one with any prop is artist Tacita Dean’s 11-year-old son, Rufus Hale, who holds his pencil and notebook. Initially too, the feet weren’t included, as seen in one of the early images of Boston artist and regular houseguest, Bing McGilvray, who is painted three times. Subjects sat on a raised plinth, against a blue and green backdrop, reminiscent of the colours of Matisse’s cut-outs, on the artist’s eye-level. The still-life was done when a sitter had to cancel, and the artist was ready to work. This is the only painting that doesn’t feature the white chair, but rather a few vegetables on a glowing blue bench. The only other punctuation in the rhythm of the whole comes from a portrait of twins, where the canvas is used horizontally, not vertically.

I doubt that this will go down as one of Hockney’s greatest series, but it shows an artist who continues to celebrate joy and vibrancy in life, and for that he deserves respect.