Obviously, none of you guys have ever shot a red carpet event before! Let me say, that I am a professional photographer, and I make 100% of my income with my camera. I shoot on average about 5-7 red carpet events per week. I'm that guy you see on TV! Let me also correct "CurtisN" and say that we are NOT paparazzi, regardless of what they may call us on the celebrity news shows on TV. Paparazzi are the a-holes that chase people and hide in bushes. We are "red carpet photographers" or "event photographers", not paparazzi.
Also, I don't know where you are supposedly seeing all these diffusers?? I rarely see people using them. A few people do, but it depends on the situation. If they *are* using a diffuser, it's most likely one of those "cups" made by Gary Fong, and even those are rare. I have a Sto-fen omnibounce, but I would never use it on the carpet. It kills too much light and it slows your recycle time on your flash significantly, even using a Quantum turbo battery pack. You also have to be fairly close to use the talent. It's a little nicer/softer light, yes. And you *can* use them direct on TTL, but it's not *that* much better to warrant losing the recycle time. I also have a Lumiquest pocket bounce I use for inside when I'm right up close.
The overhead lighting is *not* there for us. It's there for video. The PR companies who setup the events couldn't give two s**ts about lighting for the photographers. Honestly, 90% of the time I can't use the light they provide for anything other than for focusing. Depending on the setup, they might be using tungsten cans, ARRIs, HMIs, ArriSun, winter lights, and every lighting situation is different. You better believe I'm going to take some test shots! Sometimes, especially if they have a white backdrop, I will use a 1-stop C.T.O gel over my flash, and 3200k white balance to even up my flash with the video lights, but most of the time we try to overpower the video lights and not use ambient at all.
Most of the events are at night, so I'm speaking mostly about night time setups. Things on the carpet happen fast, and I want fast shots, and I want them sharp! Depending on the situation, I typically shoot at 200 or 400 ISO, with an f-stop between f6.3 and f8, with a shutter between 1/125 and 1/200, and the flash on ETTL. Depending on whether or not the subject is wearing dark clothing or light, I will kick my flash up 1/3 to 2/3 over. Each flash has its own personallity though. I know some people who always go -1/3 to get the correct exposure.
Daytime setups are completely different. Then you're just using the flash as a fill/eye catchlight, so outdoors in direct sunlight, an omni bounce is pretty pointless, unless you're really close. Daytime events are usually at the Chinese Theatre or out on Hollywood Blvd in front of the El Capitan, or in Westwood at the Village Theatre. At any of those places, we're usually about 10-15 feet away from the talent. Again, from that distance, no point in using a diffuser.
Now, with all that said... there are guys actually *on* the carpet who have a completely different style. You will usually see them shooting with their flash bounced off of a piece of paper. That's right folks, and ordinary sheet of typing paper, and a lot of times, it's the "tip sheet" PR gave us with all the talent names on it! Why bring a sheet of paper when PR will usually give you one at the event. Free bounce card, woo hoo!!
There are also some people shooting ambient with a backup camera to get "moody" shots. But you have to shoot on f2.8 to f4.0, and hold very steady. Plus your depth of field will be very shallow and most shots will be somewhat soft. But hey, that's what makes them "moody" right?
For all the time and effort I take to get great shots, the magazines really don't care. I've seen them run the most god awful pictures, fuzzy, grainy, dark, out of focus, you name it. So that's why some "pros" don't even bother to worry about quality. They know it's all about volume sales, and they still get paid regardless!
Hope that cleared a few things up you guys!