The testing is over, the teams are set, the cars are ready - the 2017 F1 season is ready to begin.

The field which will line up for the Australian Grand Prix on March 26 will be very different to the one which began the final race of 2016 in Abu Dhabi on November 27 - there is one less team after the demise of Manor, and the reigning world champion, Nico Rosberg, is also absent following his shock retirement five days after the champagne was sprayed at the Yas Marina circuit.

The official F1 driver portaits were unveiled on Monday, the stunning photos a providing a whos-who of the field for the year ahead - albeit with some notable exceptions.

Neither of the Ferrari drivers were photographed as the team do their own versions, while Mercedes' Lewis Hamilton was unable to attend.

So who are the 20 men who will be lining up in Melbourne - here's your guide...

Mercedes - Lewis Hamilton, Valtteri Bottas

Valtteri Bottas poses for his striking official portrait ahead of the 2017 F1 championship

The reigning champions, the 2016 season will be remembered as a one horse race in the constructors' championship as Mercedes went virtually unchallenged, drivers Rosberg and Hamilton winning all but two races. It was feared 2017 could be a monopoly in the drivers' championship too after Rosberg's retirement, with Hamilton out on his own, but pre-season testing indicates he could be in for some serious competition, from Ferrari in particular. Bottas, newly signed from Williams, will play second fiddle to Hamilton but should pick up his maiden F1 win at some point this campaign.

Red Bull - Daniel Ricciardo, Max Verstappen

Red Bull drivers Daniel Ricciardo (left) and Max Verstappen (right)

The only two men who stood between Mercedes and a clean sweep, Ricciardo and Verstappen each scoring a single victory - Verstappen won the Spanish GP aged 18, making him the youngest ever race winner. Although Ricciardo's car spent the first morning of testing on the back of a breakdown truck and Verstappen had some turbo issues in later tests, they should expect more than two wins this time.

Ferrari - Sebastian Vettel, Kimi Raikkonen

The Scuderia are back, the tifosi are hyped. After failing to win a single race last year - truly unacceptable for the one team truly synonymous with F1 - it looks as though Ferrari are going to be the ones to challenge the Mercedes dominance. Four time champion Vettel set the fastest pre-season lap for a decade. It wasn't even the quickest for a day though, as Raikkonen set a circuit record in Barcelona, a scarcely believable 1:18.634, 24 hours later. These are two former champions desperate to get back on top of the heap. Watch this space.

Force India - Sergio Perez, Esteban Ocon

Force India drivers Sergio Perez (left) and Esteban Ocon (right)

A best ever fourth place in the constructor's rankings in 2016 has been backed up by consistently impressive times pre-season, securing Force India's reputation as the best of the rest. Sergio Perez endured a highly unimpressive year at McLaren in 2013, finishing no higher than fifth, axed by season end and facing no future in F1 aged 23. He has rebuilt his reputation in three years at Force India and could add to his six podiums. Ocon raced nine times for Manor last season with a highest finish of 12th - no mean feat in such an uncompetitive car.

Williams - Felipe Massa, Lance Stroll

Williams drivers Felipe Massa (left) and Lance Stroll (right)

The contrast between Williams' two drivers could not be more striking: Massa, tempted out of retirement following Bottas' defection, over 250 GPs under his belt, 11 race wins, veteran of tears in 2008 when Lewis Hamilton's last corner overtake of Tmo Glock denied him the world title, and a comeback from a fractured skull in 2009 after being hit in the helmet by shrapnel. Stroll is the 18-year-old son of a Canadian billionaire, although his Euro Formula 3 title last year indicates he isn't just about the money. Such an unusual, unexpected line-up could mean this is a year of transition for the venerable British team.

McLaren - Fernando Alonso, Stoffel Vandoorne

McLaren drivers Fernando Alonso (left) and Stoffel Vandoorne (right)

Oh dear. This was supposed to be the year when everything fell back into place for McLaren, a return to the front of the grid in their retro orange livery. Instead, they haven't got through a day of testing without malfunctions in their unreliable Honda engine, and put in the least amount of laps of any team on the grid. How much humiliation double world champion Alonso, now 35, will want to endure is a big question, especially with his contract up at the end of the year. Vandoorne is a real prospect - his 10th in Bahrain last year, replacing the injured Alonso, made him the first reserve F1 driver to score points since Vettel in 2007. Should either driver get injured this year, McLaren's third driver is Jenson Button.

Toro Rosso - Carlos Sainz, Daniil Kvyat

Toro Rosso drivers Carlos Sainz (left) and Daniil Kvyat (right)

Kvyat may be the one who was bumped down from senior team Red Bull in 2016 to be replaced by Verstappen, but Sainz is the one to watch. Son of the rally driver with the same name, Sainz junior earned 46 points in last year's championship thanks to a pair of best ever sixth place finishes, and will have his eyes on a first podium this time. Kvyat will want to continue the rebuild of his reputation after his demotion, which came about after successive first lap crashes with Vettel for which he was held at fault. Toro Rosso have also changed their livery for the new season, introducing a snazzy metallic blue look.

Haas - Romain Grosjean, Kevin Magnussen

Haas drivers Romain Grosjean (left) and Kevin Magnussen (right)

This American team's debut year in F1, in a car almost entirely built of Ferrari parts, saw them come eighth of 11 and, save for Grosjean coming sixth in Australia - which meant Haas were the first debut team to score since Toyota in 2002 - make few waves. Grosjean was the only man to score points for Haas, with partner Esteban Gutierrez binned in favour of ex-McLaren driver Magnussen, who joins from Renault. Haas' aim is to challenge Force India for mid-field supremacy this time.

Renault - Nico Hulkenberg, Jolyon Palmer

Renault drivers Nico Hulkenberg (left) and Jolyon Palmer (right)

Renault will secretly be more pleased than most about McLaren's pre-season woes, which have masked a build up for a French outfit which indicates they will be hard pressed to improve on being the back markers they were last year. The highly-rated Hulkenberg is a good signing, and the first week of testing yielded speedy times, but the second was plagued by mechanical problems which led the German to say testing had fallen below expectations. Palmer's first season in F1 was dogged by the troubles caused by Renault's late takeover of Lotus, and will hope this year gives him a better chance to impress.

Sauber - Marcus Ericsson, Pascal Wehrlein

Sauber drivers Marcus Ericsson (left) and Pascal Wehrlein (right)

Two points from 21 races and doubts about the owner's long-term commitment meant 2016 was a whitewash for Sauber, but they enter this season - the 25th anniversary of their first entry into the sport - with fresh optimism. Ericsson is joined by Wehrlein, former Mercedes test driver who was the early favourite to succeed Rosberg at the team. While that would have been too big a step for him, the former Manor driver is a good pick for the Austrians. Their reserve driver is (shock horror) a woman, 23-year-old Tatiana Calderon, who would be the first female to race since 1976 should she be called up.