Hi,
Actually I believe that in the past some lenses included "ED" and aAL lenses also without being mentioned. However, in recenmt years, say last 10-15 years or so, high tech has also come into glass manufacturing. New ED glasses have come, cheaper than before and AL can be made much easier and faster than in the past by high-precision compurezied grinding or moulding of plastic elements onto ordinary glass to produce AL. Also designing of optics is now a much easier feat, due to computers. ray imaging and modeling, using so called inversion methods or even trial and error can design a lens in little time due to the massive computing powers of even desktop computers. Hasselblad was e.g., reported to have designed their own converters to very high standards using cheap software for lens modeling. SOme if not all of their new lenses to the new autofocus H1 series and digital H1D, which are not Carl Zeiss by the way but Hasselblad lenses, where probably also designed and assembled by Hasselblad even though a lot of manufacturing is done in Japan.
These methods was by the way developed in the late 60's and early 70's (to use the computing power of computers) for imaging the interior of the Earth, beign used to show the inner features of the planet and explain e.g., our magnetic field.
Cheers,
Ronald
Pentax's sudden infatuation with ED glass.
David Oswald Mon, 04 Apr 2005 19:53:50 -0700
I'm curious. In the days of 35mm SLR's, Pentax had a few ED lenses; mostly fairly long telephotos.
Now that DSLR's are the up-and-coming thing, suddenly we're seeing ED glass in the 16-45, 50-200 (as yet unreleased), and the 12-24 (newly announced). AL elements have also become more commonplace.
So the question is, what's going on here? I see a few possibilities:
* ED glass has suddenly become cheap enough to use in a broader range of lenses.
* ED glass has become necessary to produce acceptible results with DSLR's.
* ED glass has become enough of a recognized feature that using it pays dividends in improved lens sales.
* Pentax has become committed to producing better zooms than ever before, possibly to try to close the door on 3rd party lenses (much like SMC does).
Much as I love my Pentax equipment, I can't help but wonder if the sudden proliferation of ED glass in Pentax's DA lenses is because without the ED glass the lenses on DSLR's wouldn't live up to the performance of their FA equivilants in 35mm format.
The same question could apply to the proliferation of AL elements in recent lenses, though this trend actually began back around the late 90's, so it's not as new of a trend.
I would love to hear that AL and ED elements common in recent Pentax lenses represent actual improvements to image quality, size, weight, and/or cost/value over lenses produced without these types of elements. Is this actually the case?
