Archived posting to the Leica Users Group, 2001/04/17

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] RE: RE: Was Medium format camera (now pit-bull arena)
From: Jim Brick <jim_brick@agilent.com>
Date: Tue, 17 Apr 2001 17:48:56 -0700
References: <NABBLIJOIFAICKBIEPJJCEMAJCAA.darkroom@ix.netcom.com> <4.1.20010417143954.01f75d60@xsj02.sjs.agilent.com>

Well... my shields are still up. But some unkind soul, knowing this,
forwarded it to me.

- ----------------------------------------------------------------------

Austin, do you even know who Ernst Hartmann is?

What I said was conversation, not a treatise. And you are still, by not
reading what I said, adding your imaginary innuendos to my very simple
basic statements.

So you may sit there and poke and prod, again, at every nuance of every
syllable, describing for the world what you think and know, explaining what
and how other lists say and do, what is and is not standard knowledge, what
is refutable and what is not, what is impossible and what is not, etc, etc,
etc, etc... ad nauseam.

Does anyone care?

No.

Therefore, I will paraphrase my very simple statements for you in even more
simple terms.

<<
If shutter accuracy mattered, no one would own Leica M, Hasselblad 500
series, LF lens with shutter, etc.

I have a Leica R4sP that was tested, by Leica, to have a 100% accurate
shutter. An anomaly but true.

My oldest son now has the camera and is in France on his honeymoon.
>>

So Austin, do one of two things.

Read my very simple declarative post and believe that what I said is correct.

Read my very simple declarative post and believe that what I said is incorrect.

But please stop the POW style interrogations. I will never take part in
them. So save your fingers.

Jim


>At 07:08 PM 4/17/01 -0400, Austin Franklin wrote:
>>
>>Which Leica M lenses have lenses with shutters?
>>
>>I'd be curious if you happen to have the acceleration curves and/or the
>>open/close times for any leaf shutters?  That would certainly substantiate
>>or refute the claim that it doesn't matter.  My understanding that this
>>phenomenon does matter is apparently standard knowledge, and has been
>>discussed extensively on the Rollei and LF lists.
>>
>>> As a sidebar, I have an R4sP when tested by Ernst Hartmann, showed 100%
>>> shutter accuracy from 1sec to 1/1000th.
>>
>>It is almost impossible to accurately measure a leaf shutter at high speed,
>>with reasonable tolerance, without some very exotic equipment.  In order to
>>accurately measure a leaf shutter at high speed, you would have to measure
>>intensity assigning some threshold for 'open', or somehow measure only at
>>the edge.  Do you happen to know what equipment he used to make these
>>measurements?
>>
>>The claim "100% accuracy" has me curious too...since I've tested hundreds of
>>shutters, I've never seen one "100% accurate" at even one speed.  The are
>>always off by some small percentage, and of course, it depends on how much
>>precision your measuring equipment has.
>>
>>I don't want to get into a pissing contest with you, so don't make it one.
>>I would like you to substantiate your claims.  I don't care if you're right
>>or wrong, but if you are right, I'd really like to understand why, because
>>there are many people I know who claim just the opposite...and some of them
>>are professional optical engineers.

In reply to: Message from "Austin Franklin" <darkroom@ix.netcom.com> (RE: [Leica] RE: Was Medium format camera (now pit-bull arena))
Message from Jim Brick <jim_brick@agilent.com> ([Leica] RE: Was Medium format camera (now pit-bull arena))