I find that, may be most of you do agree, taking pictures in a confined room is always a challenge.
Example: Birthday celebration, talks, classroom etc.
Light source is not always adequate and even with F2.8, the speed tends to be like 1/30 or less .. even you shoot with an VR lens, the object may move and that would cause blurs in the picture.
An with F2.8, there could be another problem, the optical quality is not always the sharpest at F2.8 .. but like F11 or something.
Jacking up ISO is an option, but you rarely want to go beyond 1000. Even that, in some occasions the speed is still could be lower than 1/50s.
Then using intelligent flash (like SB800 for Nikon), but you know the light is still inadequate for the relatively large room.
What should we do then? To shoot a crispy sharp picture for the entire room that capture everyone (say some 20-30 people) in the room?