Shooting from the back of the room...

...is exactly how I don't like to do my event photography, but I was working with a team of photographers, and this is the assignment that was given to me. It proved to be a useful problem-solving opportunity, so I'll share my experience in case any of you can benefit or offer alternatives.

Having worked in the space before, I knew I'd be about 100' from the stage and that it probably wouldn't be very bright. I'm not a sports shooter, so my longest lens was a Tamron 70-300mm f4.5-6.3. Not sure if the stage lighting would suffice, I set up a pair of speedlights aimed at the stage. Good thing I did, because, while I switched back and forth between flash and ambient, the latter shots weren't great, pushing up against ISO 25,600.

Afterward, I wished for a 100-300/4, but then realized that even f4, with the fast shutter speeds needed to freeze motion, wouldn't help a whole lot. So, I've resigned myself to using flash in that kind of situation. I don't like it because it's hard to get just the right facial expression of a speaker with just one frame every few seconds. C'est la vie. Once I'd accepted the need to use flash, I realized that I really didn't need a bright lens, which led to the rather radical thought that my FZ1000 MkII would probably do the job nearly as well as the 70-300 on my a7RIII. Hmm.

No questions here, but ideas welcome.

Sometimes a 200 mm f/2 is useful in these sorts of situations. Unless you can set up radio-controlled lighting distant from your location, I don't think the quality of flash lighting from 100 feet away is always going to be pleasing.

Thanks for chiming in. In a smaller space, I would have just used my 135/1.8 in Crop Mode. But, in this space 200mm was too short, and I couldn't get closer because my shooting position was on a staircase at the back of the densely packed room.
I used radio-controlled speedlights set manually, positioned about 75' from the stage on both sides of the room, with the heads zoomed to 200mm to focus their meager power on the stage. I've used similar setups for lighting stages many times before, and it actually looks pretty nice, especially with a 2:1 ratio. I mean, it's not portrait lighting, but it looks like, well, a lit stage. Besides which, the only way to avoid the point-source look would be to position four heads with large softboxes, or a 10'x12' scrim, on either side, and that's not happening. And, no, wall or ceiling bounce with 1200WS heads wouldn't have been an option even if I'd had the gear.