Re: [Leica] Where are the engineers? was: New Macro-Adapter with other M lenses

[Henning Wulff <henningw@archiphoto.com>]

At 1:41 PM -0400 9/24/03, P2CON@aol.com wrote:
>Lucien, I think you are again mistaken. In my post from yesterday, I 
>postulated that the new lens will have the same RF cam design as the 
>old 90 Elmar screw-mount and the thin Tele Elmarit 90/f2.8, which is 
>a cylinder. It will act on the cam follower in the eye attachment in 
>the same fashion that it acts on the RF wheel in the camera. It will 
>have the same bayonet pattern as the older 90TE. When mounted upside 
>down on the eye attachment, it will show the distance scale for the 
>close distances, and will act on the push-rod cam follower of the 
>attachment to move the camera body RF wheel.
>When mounted normally on the body it will show the distance scale 
>from 1m to infinity and will act directly on the RF wheel in the 
>body just as do the older lenses with a cylindrical cam.

This would work if the throw of the new lens in its focussing range 
is 150 degrees or less. Then the two cams can be ground on the one 
cylinder. On my thin Tele-E the throw is just over 180 degrees, so 
the length of the grinding of the cam cylinder to adjust it for this 
specific lens and exact focal length, makes it impossible for another 
cam to be ground on the opposite side that is adjusted for the macro 
range with the adapter, because the two would overlap.

>You are perhaps being mislead by thinking that the new lens will use 
>a push-rod cam mechanism.
>
>Regards, Paul Connet
>
>Lucien answers Dan's comment:
>>>Dan says:
>>  > No, I meant that it would seem that if the lens can mount in both the
>>  > adaptor and the camera body directly, then the mounts in the camera
>>  > body
>>  > and the adaptor can't be that dissimilar.
>>
>>  Dan,
>>  They are.
>>  Compare the bayonet on the Macro-Adapter and the bayonet on your camera
>>  body.
>>  On the adaptor, the lock is on the opposite side as on the camera.
>>  Which means that on the Macro-Elmar 90mm there will be two cam at 180
>>  degree of each other.
>>  One used when the lens is mounted directly on the camera
>>  and one use
>>  only with the adaptor.
>>
>  > Lucien

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    *            Henning J. Wulff
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