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- From: dbernard@clesun.Central.Sun.COM (Dave Bernard)
- Newsgroups: rec.photo
- Subject: What does ED glass really buy you?
- Date: 21 Jan 1993 16:07:19 GMT
- Organization: Sun Microsystems
- Lines: 17
- Distribution: world
- Message-ID: <1jmhnoINNqbr@cronkite.Central.Sun.COM>
- References: <1993Jan21.094446.12281@sactoh0.sac.ca.us>
- Reply-To: dbernard@clesun.Central.Sun.COM
- NNTP-Posting-Host: clesun.central.sun.com
-
- My understanding is that the ultra-expensive telephoto and
- zoom lenses featuring ED-type elements allows colors in
- whatever wavelength to focus on a single plane. My question
- is, if you take a non-ED lens of the same focal length, and
- stop it down several stops, would not the inherent depth of
- focus at the film plane have much the same effect, esp. with
- a subject focussed at infinity? In other words, would the
- ED type lenses really come into their own when used at near
- fully open apertures... which kind of implies that the photographer
- wanted to either hand hold, or for some other reason wanted to
- maximize shutter speed (sports, nature)? What it comes down to,
- for tripod-mounted landscape use, with small apertures, is there
- any advantage to ED?
-
- Dave
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