----- Original Message ----- From: <fotofx@ix.netcom.com> To: "List for Photo/Imaging Educators - Professionals - Students" <photoforum@listserver.isc.rit.edu> Cc: "List for Photo/Imaging Educators - Professionals - Students" <photoforum@listserver.isc.rit.edu> Sent: Tuesday, December 24, 2002 3:34 PM Subject: RE: Fast Lenses: Why so expensive? > Hi All, > > The main reason the lenses cost more are the following: > > The fast lenses use more exotic elements inside Flourite, UD, etc > > The fast lenses are often made of extremely high grade and light weight metals > titanium, magnesium etc. Also they often contain high end and exotic > composite materials. And tougher and better electronics, more switches gears > and rings. > > The lenses are also more expensive to make. > > Fast glass does not sell real well, meaning a given camera company will sell > loads more tele zooms than it will 400 2.8. So the price is higher to pay the > R&D, and manufacturing costs with a small profit built in. > > Happy holidaze, > > Les > > > Kevin, there are a lot of factors that go into > > lens costs. Lets look at a > > few things in layman's terms. A lens with a > > max opening of F5.6 has more > > depth of field than a lens of F2.8. The > > reason to buy a fast lens is to > > shoot it wide open typically. Focusing > > errors, lens aberrations > > and distortions show up in lens when they are > > either shot wide open or > > stopped down to their maximum. Thats why > > F8-F11 are considered the sweet > > spots in lenses. Most lenses are turned to > > produce the best picture at > > those F stops. > > > > The F2.8 lenses and faster have to be tuned for > > a wider range of > > apertures. Lens elements must meet much more > > stringent quality > > controls. The lens elements are bigger and > > harder to make. There are > > typically more elements to correct for various > > distortions along the > > way. The heaver glass needs more heavy duty > > gears and motors to > > auto-focus them. It all adds up to a more > > expensive lens. > > > > Hope that helps explain it.... > > > > > > Happy Holidays, > > Rob > > -- > > Rob Miracle > > Photographic Miracles > > 203 Carpenter Brook Dr. > > Cary, NC 27519 > > http://www.photo-miracles.com > > > > > The invention of the lens begins in the mid 1800's to increase spped so subjects don't have to stand so still. Therefore, development of a 'fast' lens has been the subject of what can be shown as the advancement of the photographic lens, ever since. Contrary to what my occur to many, a faster lens has at least one, or more EXTRA elements to "disperse the light after entering the lens chamber" such is the case with the Sonnar, which has an extra element behind what is essentially a Plannar lens. The Sonnar adds an extra stop by this dispersal principle. Schneider's Krochnock (spelling?) has that extra element in the middle between two double anastigmatic elements, and does the same dispersal trick to increase the speed of the taking nature of light capture as it fills the film plane. Extra cost? Who's to say whether it's a matter of demand, . . . but the engineering and assembly, coupled with the fact that there is an extra element or set of elements would certainly add to the cost. How did I do, Knoppow? :) Merry Christmas everyone, Steve Shapiro, Carmel, CA
