I find myself repeating a lot of things lately on here about these sorts of things, and I am not trying to be rude or have anything against you, this is a general statement.
Before I repeat this for the third time in the last two days, I highly encourage people to NOT use NS as a reliable source of information regarding cameras. Go where the true professionals are (ex: dvxuser.com). Many people on here dont know as much as you think (myself included) and get things mixed up or are misinformed. This doesnt mean they are dumb. There are some pretty smart camera people on here that post, Horner, Landis, Will, E Heath, ect (I apologize if i left out someone, im speaking in terms of video). Things can be said differently and come out wrong. I could go on about why but I know that other camera nerds like me on here dont come to NS for camera information. We are all willing to share what we know, but its not always entirely accurate and can have many holes.
With that said, onto my repeat...
There is no such thing as a "video specific" lens for DSRLs. DSLRs are NOT video cameras. They are still cameras that shoot video. Thus, no auto focus, servo zoom, aliasing, 4:2:0 ect, ect, ect (lots of differences, look them up). If its a good still lens, its good for video. If its not good for stills, its probably not good for video.
With that said, there are such thing as video specific detachable lenses, known as "cine style" lenses, which are usually just talked about as cine style zooms. They were designed for video cameras such as the RED and anything that really came before this HDSLR craze. They are extremely heavy and expensive (a cheap 3 lens kit would cost around 6-10 gs and the lightest probably weighs around 10 pounds). I wish I could tell you more then that about them, but I really cant, since I cant say I have ever had a chance to touch one or even think about it.
Panny is also developing some new cheaper lenses themselves for their new AF100 that are supposed to be "video lenses." They will be different then these cine style lenses and much cheaper. The main thing about them is that they use Panasonics OIS (optical image stabilizer) technology and are supposed to be able to auto focus while shooting (something dslr lenses cant do, since they are after all for stills and not video), but it is already being rumored that they auto focus like a DSLR lense, which is not practical for video. This means loud, slow and snappy, rather then quickly easing into the proper focus.
I could really go on, but my point was, dont use NS as your main source for camera info and there is currently no such thing as a DSLR lens for video. They are developed for stills and everything I listed that isnt for still doesnt work on DSLRs as far as I know.
Also, the other thread already has a ton of good usefully information in it.
Hope that helped clear things up :).
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