----- Original Message -----
From: "Mike Johnston"
Subject: Re: 67 equipment, request for enablement
> Redoubtable William Robb wrote:
>
> > I love my 90mm LS...The 90mm LS is also a great lens.
>
>
> How does that lens work? Is there any special extra step you
have to take in
> operating it on the P67?
It works pretty well, considering it is a bastard marriage of
two technologies. The camera shutter must be used at 1/8th
second or "B" if the lens shutter is going to be used. Note, the
lens can be used without using the lens shutter. the lens
shutter speed should be set prior to cocking it. If using flash,
the sync cord is plugged into the lens. There is also a cable
release socket on the lens for facilitating multiple exposures
with the camre shutter on B.
One thing that I hadn't thought of when I bought the lens is
it's usefulness for action stopping. With the 1/30th second
shutter duration on the camera, it is possible to get quite a
lot of subject movement during exposure. The lens shutter
eliminates this problem.
So here are the steps for operating the LS lens:
Set the camera to 1/8 second. Set the lens shutter to the
desired speed. Cock the lens shutter and camera shutter. Take
the picture.
The mechanical complexity of what happens is quite marvelous.
When the shutter button is depressed, the reflex mirror swings
up and the lens stops down. At this point the lens shutter
closes. I presume there is some sort of mechanical delay buit
into the lens shutter, because it is actuated by the aperture
coupling. When the mirror is out of the way, the focal plane
shutter opens, then the lens shutter cycles, the camera shutter
closes, the mirror swings down and the lens shutter opnes again.
The reason I was given for the 1/8 second time on the focal
plane shutter is to give the lens the time it needs to cycle
through all the steps it needs to go through, and deviating from
it can damage the shutter mechanism.
William Robb
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