Above: All emblems from chapter 5
Emblem 1: As Chris, you’ll need to crawl through a fan that Piers stops for you early in the chapter. Once you stand up, you can see the emblem right in front of you. If you’re Piers, you can shoot through the floor grating to hit this emblem before or after you shut off the fan.
Emblem 2: After Chris and Piers meet up again on the elevator, they'll next encounter a door requiring them both to pry it open. As soon as you pass through that door, look up and to the right (take out the two enemies that enter first, if you wish). The emblem is in the high passage way where the J'avo spawn.
Emblem 3: During your run through the tube, you’ll reach a section where all is quiet. Simply look down at the ground to the side to find an emblem.
Emblem 4: Just before the third flesh barrier, look to your right. You’ll find an emblem on the wall, though you don’t have much time to shoot it.