With a camera, I can make casting look however I want it to look. All I have to do is change camera angles and/or casting angles and I can tighten my loops, reduce counterflex, hide a haul, or even just make stuff up (as long as I don't show the frames that would undo such sleight of hand). For a rather large, new, dead-tree project, I shot several bazillion minutes of high-speed HD video (at least 60 frames-per-second (fps)). I shot from a variety of angles, all of which you could duplicate yourself with nothing more than a tripod, a ladder, and a higher-end smartphone. I chose angles that showed aspects of the casts that were most important to the discussion. But...if one were to use some of those same shots to support a very different conclusion/theory/bit-o-magic, then the pics might actually be useless (or at least not realistic).
So, if you're gonna video casting, make *sure* that your camera is set up to show the truth, the whole truth and nothing but the truth. Even if that means your favorite pet theory gets euthanized as a result. Sometimes you have to compromise your camera/casting angles in order to capture only that one part of the cast that's most important (see the larger Spey family of casts, with multiple changes of direction, as an example). That's not cheating, that's just prioritizing. Change angles if you really need to focus on another part of such casts. Changing angles might be hard, and even require actual work. Do it if you want to be taken seriously these days.
That said, how do you know you've got it right? Well, if I wanted to show the vertical structure of a loop as it forms, for example, I'd shoot with the camera at right-angles to the loop plane (as best as I reasonably could). That could mean having to shoot *downward* or *upward* to actually get the shot (elliptical or side-arm casts anyone?). Shooting at a significantly reduced angle to the loop plane *would not* reveal the real things going on. Imagination and "I say so" doesn't cut it. Loop shape/tightness/counterflex/rebound/etc would not be truly discernible. Another example: Shooting at a low frame rate, like 24 to 30 fps (that's "normal" video). You might not get what you need/want/hope/don't hope to see; you also might miss something important in the gaps of time where the rod is moving fastest. Shoot at least 60fps if you really need detail, or even better, 120 or 240. And be prepared to see things that you might wish *weren't* true, especially if a personal theory is on the chopping block.
I have been fortunate enough to shoot a fair amount of 3-D motion capture footage over the years. That footage is computer captured and reveals *everything* from *every* angle (and as point-by-point data, not just images). You can't hide much in there. It's fantastic (I think), but most people aren't going to get that opportunity. So, do the next best thing and shoot your video the right way. Not only will it help you see what's really going on, but it will also help others who might like to truly see what you're doing.
Below are some illustrated video frames (from my new book), with captions. Each shows how casting/camera angles can reveal or obscure the real goings-on.
Oh, one more thing: How do you know the illustrations are based on real video frames, and aren't just my "adjustments"? Easy, I can't draw that well, so I have to trace! ;)