From what I've gathered, fast lenses are (generally) more difficult to make than slower ones, and zooms are more difficult to make than primes. I would venture to guess that a zoom with that sort of speed would be prohibitively priced and not cost effective, if even feasible in the first place. As for impossible... I don't know enough about optics to say yay or nay though, besides the fact that your lens barrel is probably going to get bigger and bigger and not be possible at SOME point. There are, for the record, lenses faster than 1.4, but their cost goes up quickly. Canon's 1.2 50mm is something like 1500 and the 85 is nearly 2000.The fastest lens that I've ever heard of is the Zeiss 50mm .7. Also, video lenses have very fast apertures and a wide range of zoom, but do not, from what I understand, offer the same resolving power.
Message edited by author 2010-01-12 22:27:46. |
