When shooting keynotes, use a wide lens like a 24-70 and a telephoto like a 70-200. Always have two bodies with you as there is not enough time to be switching lenses. Have a medium telephoto prime ready like an 85 1.8 to 1.2 for audience low light shots.
Get a great variety of shots from different angles and framing. Aim for 8-10 keepers per angle
Additional Tips:
Shooting the audience is one of the toughest parts of a keynote due to the lighting conditions. In most cases, they will be in low light conditions. This is where prime lenses will help.
Additional Tips: