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From: kanner@tymix.UUCP (Herb Kanner)
Newsgroups: net.rec.photo
Subject: Re: filters
Message-ID: <595@tymix.UUCP>
Date: Wed, 18-Dec-85 00:14:02 EST
Article-I.D.: tymix.595
Posted: Wed Dec 18 00:14:02 1985
Date-Received: Fri, 20-Dec-85 01:48:12 EST
References: <1002@homxb.UUCP> <394@sdcc13.UUCP>
Reply-To: kanner@tymix.UUCP (Herb Kanner)
Organization: Tymnet Inc., Cupertino CA
Lines: 28
Summary: 

In article <394@sdcc13.UUCP> kemasa@sdcc13.UUCP (kemasa) writes:
>	Neutral Density filters do this job and come in several densities,
>it is also useful if you want a more limited depth of field with normal
>films and/or slower shutter speeds.  There are filter to do just about
>anything, photo magazines sometimes have articles on different filters.
>As a side note I hope you and everyone reading this uses a filter all
>the time to protect the lens, like a UV filter or whatever.  I don't know
>if this has been brought up before or not, but it can really save your
>lens.
>
>					Kemasa.

The notion of always protecting a lens with a low-effect filter, such as a
UV filter, is considered very controversial among professional
photographers.  The reason is that any extra glass-to air interface, even
with modern coatings, reduces image contrast measurably.  I have read
articles or chapters in books in which it is recommended to use the UV
filter either when it is needed, or when one is in a hostile environment,
such as the sea shore.

Personally, I have compromised.  I do not keep a filter in simple lenses,
which can be replaced for between $50 and $100.  I do keep a filter in zoom
lenses and vari-focal lenses.

-- 
Herb Kanner
Tymnet, Inc.
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