[Leica] Re: Testing & manufacturing techniques at Solms

[Jim Brick <jim@brick.org>]

OK Doug, you win.

Leica products are 100% exhaustively tested.

So now I don't understand why there are so many R8 problems, M6 pressure
plate, shutter, RF alignment problems, and lenses with loose elements??? So
is this all happening "after" they leave Solms?

Actually, my statement still stands. Leica cannot exhaustively test each
and every piece of equipment, well enough, to produce a 100% flawless
yield. No matter what you think, from your observations, it simply cannot
happen.

Jim


At 10:40 AM 4/23/99 +0000, you wrote:
>Jim Brick <jim@brick.org> replied re Leica 100% testing
>
>>Yes, I know. But testing each item, and "exhaustively" testing each
>item,
>is two different things. If each item were exhaustively tested, we
>would
>have "no" DOA's, scratched film, RF mis-alignment, etc, etc, etc.
>
>I must say the level of testing I saw at Solms looked very thorough.
>When Leica says tested they mean TESTED!
>
>One test gadget consists of a turntable on which a lens can be mounted
>facing upwards, but with a slight off-axis tilt. A narrow beam of
>light (laser I think) is projected down into the lens, and the latter
>is turned. This process is intended to detect if any of the elements
>is incorrectly centred.
>
>Sadly, no inspection, no matter how careful, is likely to have
>prevented the problems I'm having with my 12 year old M6. All were
>what I'd classify as premature deterioration due to poor worksmanship
>or materials in a camera which had seen little or no use until I
>bought it.
>
>I have never had a problem with a pre-1974 Leica camera or lens which
>could not be ascribed to the fair wear and tear clocked up in quarter
>of a century or more of use (e.g crumbling vulcanite or inoperative
>slow speeds).  However, of the ten post-1974 items I own, four have
>failed in use, while a fifth proved dead-on-arrival when unpacked by
>the dealer. Much through I'm attracted by the new Tri-Elmar, that 50%
>failure rate of post-1974 equipment makes me very reluctant to buy
>one.
>
>On a happier note, one thing I learned at Solms which came as a
>surprise was that the traditional method of grinding lenses in which
>several blanks are mounted on a hemispherical surface and ground by a
>single tool is no longer used. Machinery of this type had been used at
>Wetzlar and re-installed at Solms, but the Leica company soon found
>that this time-honoured technique was not good enough for the latest
>generation of lenses. Now the individual glass elements are moulded to
>approximate shape at the glass works, then individually ground at
>Solms on a computer-controlled machine. Each surface takes around 20 -
>40 seconds to grind.
>
>Regards,
>
>Doug Richardson
>