[Leica] Facts versus opinions - can I explain in more detail what I meant?

["Doug Richardson" <doug@meditor.demon.co.uk>]

Buzz Hausner <Buzz@marianmanor.org> wrote:

>I presume that your post refereed to Marc Small's recent
response to the UV filter question.  It is true that Marc can be
rather
definite in his feelings, but as one who has challenged Marc and been
the
recipient of more than one of his thoughtful screeds (eh, Marc?), I
can say
that they never consist of opinion dressed as fact.

I wasn't specifically responding to Marc's posting, but reacting to
the hostile tone of many threads in recent months.

One of the topics which came up during the London LUGmeet last
November was the fact that here was a group of LUGnuts drinking beer
and talking Leica for hours on end, swapping lenses, advice,
reminscences, tall stories etc, without a single squabble. Someone
(can't remember who) commented "Why can't the LUG be like this?"

My comment about opinion versus fact was not intended to suggest that
anyone is deliberately giving false or misleading information, but an
expression of my concern that opinions are often presented with a
degree of forcefullness which makes them look like facts, and in some
cases are defended (perhaps not by the original poster) with a zeal
which elevates them to dogma.  It was not an attack on anyone -
particularly not Marc, whom I've always found to be an unstinting
source of advice. Indeed it was his enthusiasm for the marque which
finally presuaded me to buy a pre-war example of a Certain Other
(Zeiss) Camera.

Let me try to give an example of what I mean by opinions and facts.

When Nathan Wajsman asked a few days ago about operating instructions
for his IIIf, people sent him replies which were facts - how to erect
the lens, and set the slow speeds etc. Because we are dealing with
facts, all the advice Nathan received gave similar information. It
caused no flame wars or name-calling.

But let's take the case of our UV filter debate, which is a good
example of the point I was trying to make.

Several posting on this subject have explained that the cement used in
recent Leica lenses acts as a UV filter, so such lenses don't need
separate filters to hold back the UV light. Adding another layer of
glass in the form of a filter increases by some degree the chance of
flare.

You can find this information in Leica company literature, and
textbooks on photography, so it seems safe to say that these are
facts.

But is the older Leitz-era lens I bought last month new enough to have
this UV absorbing cement? here we're approaching the borderline
between facts and opinions. Unless the lens was designed after the
introduction of the new cement, then most people's answer to that
question would be an opinion. If the marketing literature for that
lens had not mentioned the type of cement used, then the only
definitive answer would have to come from Leica archives, or even the
retired Wetzlarites who made the lens type in question, or from
technicians who've had to split apart and re-bond the elements in this
type of lens.

Whether a UV filter provides a useful degree of protection to a lens
front element, whether an individual user needs that protection, and
whether any image degradation created by the filter is a price worth
paying for that protection are (I would suggest) value judgements for
the individual photographer, and thus a matter of opinion in which
there is no "right" or "wrong" answer.

Some of us feel very strongly that a UV filter performs no useful
protection function. However, Theo Kisselbach, (a former head of the
Leica Academy, I seem to recall), has written that a UV filter "can be
left permanently on the lens, since it has no unwanted effects, and at
the same time provides very effective protection of the front lens
against dirt, sand, or sea spray".

We have here two conflicting pieces of advice. I'm suggesting that
this is not because one is right and the other wrong, but because we
are dealing with opinions, not hard facts. Kisselbach qualifies what
he is saying with the words "can be", so that keeping the UV
permanently mounted filter is an option. By contrast, the tone of some
anti-filter posting has been much more dogmatic, along the lines of
"Don't do it - it's wrong - we who know  have spoken - there is
nothing more to discuss."

I'm suggesting was that when we post, we should remember that in many
cases what we may personally regard as "fact" is in practice our
strongly-held opinion.


In response to my posting on "One-sided flame wars" Bernard
<5521.g23@g23.relcom.ru> wrote:

>Oh, really? Now that's just your opinion.

Yes, that's what my posting was - opinion - it wasn't pretending to be
anything else. And individual readers are free to agree, disagree,
ignore it, or delete it as they see fit. Or even to find flaws in my
reasoning and point these out to me.

Buzz makes the point that "like many symbiotic relationships, the kin
in this family often bicker and call one another appalling names.  Its
a sibling thing and to be expected."  I guess it's my age, or a
combination of my age and European culture (a dour Scots upbringing),
but I don't expect it, and get upset when I read it.

Now the fact that I get upset is no big deal, but one result of the
bickering is that some people don't want to post messages publicly.
People have even resigned from the list because they don't like the
squabbling. Neither trend is good for the long-term future of the LUG.

Regards,

Doug Richardson