Here is the full list of all 12 Photo Finish achievements.
Finish 20 matches
Finish 50 matches
Land on other players 10 times
Recieve a total of 100 damage from the harvester
Win a round with each vehicle
Win a round with each character
Travel a total of 100 miles
Travel a total of 5 miles through deadzones
Win a game with one ai player 10 times
Win a four player game 10 times
Deal a total of 1,000 damage
Deal a total of 10,000 damage