What's the difference between the quality of video lenses versus still lenses? Broadcast video lenses (and Professionals, to an extent) cost so much more than SLRs, why is that? I understand that video lenses need to operate differently with respect to zoom and focus, as well as use high-quality servo controllers. Is the SLR glass of better quality than Broadcast video lens glass? More elements in video lenses? Coatings? Breathing?
And, a step further, the difference between SLR primes and video/film primes?
Interesting ponder. I don't really have much clue when it comes to SLR lenses, but if I were to take a wild guess, I'd agree that servos and more lens elements is a big part of the equation. For one, video lenses have a set of elements in them to maintain focus while zooming, most have built-in extenders, and my impression is they generally have greater zoom ranges (starting around 15-20x) and smaller f-numbers (larger apertures). And since every moving part needs to be remote-controllable, I'd guess that comes with a price in servos, too.
But again, I'm really just making a qualified guess here, since I don't know much about the "features" of SLR lenses. Feel free to educate me, though :-)