My volunteer assignment was to shoot conferece picture in low light hotel conference hall, to cover 200-300 crowd, key note speaker and big screen presentation (Power Point). I used no flash but slow speed, high ISO and tripod to capture the whole room picture. The whole room picture was fine but the on screen presentation was always over. It took me long hours to rectify it by PS. Under such extreme situation, can I use "dragging the shutter" technique and compensate by a on camera SB-800 to cover the 300 people in front of me and key note speaker on stage ? I tried to use ceiling reflective flash shooting from the back row and getting a normal exposure of people from the back rows to the centre of the hall, and the under exposure of screen display (not ideal, but better than over exposure). However, the key note speaker on stage was so dark becasue he was too far away (100 ft) from my SB800. As suggested by experts in this forum, I rent fast lens to do the job but just can't balance the screen display and the crowd. I really want to know how to shoot an good conference picture to cover everything in the conference hall without PS. Thanks.