Re: Filters

[Jim Brick <jim@brick.org>]

At 05:45 AM 9/23/97 -0700, you wrote:
>I recently acquired an M6 with a 50mm lens.  Does a filter placed on the 
>lens degrade it's capabilities?  I'm a working photographer and have 
>always used a filter for protection.  They have saved my senses in more 
>than one occassion.
>I have also noticed "Wetzler" in some of the lens ads.  How do these 
>lenses differ from other Leica lenses?
>I'm going to have to complete the system with used lenses.  Would someone 
>kindly recommend a book which will tell me how to read the serial numbers 
> to deturmine the age of the lens?  
>Thanks,
>Jack
>

Jack, much of this is a repeat of my post of last May.

So what is the reason for the UV (protection) filter??? Since 1965, Leica
glass & glue contain all of the UV filtering you will need (per Leitz
document #920-083.) A useful filter (polarizer, warming, conversion, etc.)
is OK when necessary. But don't put useless glass in front of your very
expensive, multicoated, meticulously designed lens. As Leica said a number
of years ago "If we had wanted a piece of glass in front of our lenses, we
would have designed it there. But we don't and we didn't." I believe I
first heard this from Walter Heun, perhaps Walter Moffat.  In my humble
opinion, IX-NAY on the UV! UV (protection) filters and nEver-Ready cases
are profit boosters for camera stores. Think you need front element
protection? Use a lens cap. More Leica words... "Even high quality filters
may create problems in certain situations. High contrast, sunrise, sunset,
night shots, bright light sources in the frame. These can cause general
degradation of the image, loss of contrast, and double image. Remove all
filters in these kinds of situations." ... per Leitz document #920-083. So
what constitutes high contrast? How bright is bright? Conclusion... only
use a filter if it is going to _enhance_ the photograph. So how is a
protection filter going to enhance an image taken through a modern Leica
lens? It cannot enhance, it can only degrade.

I got my first camera in 1948. I worked as yearbook photographer, belonged
to all camera clubs in schools through regular college, then went through
Brooks Inst. of Photography (1960/61). This is 1997. Of the literally
thousands of photographers I know & have known, not a single one has bashed
the front element of his/her lens. I guess it can happen, but it's probably
as rare as a person getting hit by a meteorite. I'm sure someone on this
list has done this. They should be watching the sky when not looking
through the viewfinder. The most common accident... dropping the whole
camera or having it tip over on a tripod. This happened to George Lepp just
a few months ago. When you drop your camera, it usually damages a whole lot
more than the front element of your lens. As a matter of fact, the front
element is rarely, if ever, touched. Leica 19mm, 16mm, and 15mm R lenses
have no filter threads. The 15mm glass is huge and sticks way out. I own
and often use this lens. These are expensive tools. Even though they are
tools, they should always be treated with respect. If you need to keep your
lens covered with another piece of glass to "protect" it, in my estimation,
you are doing something wrong. The hit would have to be dead center in the
middle of the filter (a really really rare situation) to ONLY damage the
filter, and not take out the edge of the lens barrel in the process.

As you can guess, I have a STRONG opinion on this subject. Other people
have legitimate opinions as well. So take my opinion, as well as other
opinions, into account when you think this through. Sometimes it simply
your own peace of mind that will dictate what you do. All the technical
talk in the world won't help.

Jim

ps... sorry, cannot help you with the serial numbers. There are plenty of
other people here that can answer that.