Joey did a fair job there
Now then. I’ll address the O.P. first, then branch out a wee tad here. I live this shit. Video camera are indeed capable of eliminating the roll bar these days. The two main producers of broadcast quality video cameras are Sony and Ikegami. Both models, for years, have allowed the operator to seek a matching cycle. For example, I am shooting Joey Baggadonuts, and behind him is an NEC MultiSync monitor. I frame up, and then while looking through the eyepiece, scroll through the various sync rates, i.e.- 66.8 mHz, 70.0 mHz, etc. As one scrolls through, the bar on the monitor will turn to a flicker, then voila. You will have hit the matching refresh rate for that PARTICULAR monitor. You do your shot, all looks lovely. HOWEVER- if you have to PAN the camera, the image will shudder as you do so. Refresh is actually a slanted action, the retrace line moves in a diagonal axis across the inside of the CRT. So, if I pan, I get a shudder. Oh well.
Now, to beat a question or to answer before it’s asked. When you see a t.v. show where there are LOTS of monitors in a shot, the odds are incredibly high that they are matched monitors. Either by brand and model, OR the individual PC’s have been run on a refresh program. I used to have one, a bazillion years ago, before you could actually chose the rate on the face of your monitor. I can remember saving the day with it. ( This is pre- sync by camera days). Additionally, if you see a shot in a t.v. show with lots of monitors,and it’s a dramatic show, the odds are excellent that it was shot with a film camera, NOT a videotape camera. We’ll get to that in a moment.
The real problem is the real world. I have done shots on the floor of the NYSE. They had monitors there I’d never seen in my LIFE before. C’est la vie. I left the camera on Pre-Set ( 60hz, 30 fps ), and let them all roll as they would. You can only chose one rate for the camera to match to.
Now, to film cameras and t.v. shows. Shows such as Lou Grant, etc where you are in an office FILLED with monitors ( newspaper, police station, etc). Depending on the film camera body, you have to have a mechanism by which you can adjust the frame rate by fractions of a frame per second. In the older days, you had an add-on box that would drive the camera by said fractions. Videotape sync for a film camera is NOT 30 frames per second. ( Videotape is recorded by a video camera at 30 fps. in the united states, at a 60 Hz cycle). When shooting a video image with a film camera, you shoot at 29.975 frames per second. However, the world is filled with funky monitors. NTSC ( the broadcast standard in America ) rolls at 30 fps. BUT- that’s just if you have a t.v. set in the shot. If you have a computer monitor, you have to set the film camera, in a way similar to that of a videotape camera. Newer generation film cameras made by Arriflex, Panavision and Aaton tend to have software built in that permits “phase shifting” to occur as you roll. This way, the first few feet are exposed as you adjust the fractional frames per second shot, until the percieved roll bar disappears from the eyepiece. Then of course, you leave the camera rolling, and do the take.
I shot a commercial for ESPN last summer,and FINALLY got to use a camera with a true “smart box”. It remembered the off-speed sync rate, even after you turned the camera off at the end of the shot. You just had to program it once, then you were good to go. Unless you cut power to said smart box. Then you had to re-set it.
Hope this has been at least a little bit helpful. Oh, and the flashing of spread fingers in front of your eyeballs, and the wagon wheel spokes is less a sync issue and more an issue of stroboscopic effect. <sigh> I can’t do that one now, and besides it’d be a major-league hijack.