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Path: utzoo!watmath!watcgl!dmmartindale
From: dmmartindale@watcgl.UUCP (Dave Martindale)
Newsgroups: net.rec.photo
Subject: Re: don't use filters to protect lens
Message-ID: <3045@watcgl.UUCP>
Date: Sat, 1-Sep-84 05:39:10 EDT
Article-I.D.: watcgl.3045
Posted: Sat Sep  1 05:39:10 1984
Date-Received: Sat, 1-Sep-84 15:03:27 EDT
References: <3466@decwrl.UUCP>
Organization: U of Waterloo, Ontario
Lines: 32

I realize that using a filter will inevitably degrade the image from a lens.
But in some situations, it doesn't matter much.  For example, I do a lot
of shooting of people in available light, and I haven't the time or the
finder brightness to focus extremely critically (and people move continuously
anyway).  And for me, leaving on a filter by default gives me some peace
of mind that is worthwhile:

	1) though I've not done this yet, several friends have had impacts
	   to their lenses hard enough to bend the filter ring or break the
	   filter glass.  These would have been much more serious accidents
	   without the filter.

	2) I have a permanent fingerprint on the lens of a pair of binoculars
	   where someone touched it and I didn't notice it for several months.
	   By that time, fingerprint oils had attacked the lens coating.
	   If this ever happens to my camera, I'd rather it happened to the
	   filter than the front element of the lens.
	3) (irrational reason): I don't feel very guilty using Kleenex or
	   my shirt or whatever is at hand to clean the filter when it gets
	   grundgy.  If I scratch it inadvertently, that's life.  I can't
	   be quite as cavalier about my new $250 lens.

If your Leica manuals specifically warn about not using skylight-type filters,
I'd tend to heed them - they should know what they are talking about.
But my manuals seem to suggest that using UV or 1A to protect the lens is
generally OK.

When I'm worried about getting the greatest possible contrast and resolution,
I won't use a filter unless I absolutely have to.  But then I'll also use a
fixed lens instead of a zoom under these conditions.  And I suspect that
the presence of a filter (at least if it's a good one) matters less than
the choice of lens.