[pure-silver] Re: old rollei over exposing
- From: "Gene Johnson" <genej2@xxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Fri, 18 Feb 2005 11:01:38 -0800
Yeah thats me alright. Setting off those alarms wherever I go...
----- Original Message -----
From: "Shannon Stoney" <sstoney@xxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Friday, February 18, 2005 8:23 AM
Subject: [pure-silver] Re: old rollei over exposing
> >I agree with Mr. Knoppow,
> >
> >Though both of the failed mainsprings I've actually seen were broken as a
> >result of a crack started from a spot of surface corrosion.
> >
> >I have seen several synchro-compurs on old Rolleiflex MX's that were just
> >plain worn out. The first symptom is usually a failure to cock the
shutter
> >when the board is extended outward. The wear on all the cocking
mechanism
> >parts stacks up to the point where there isn't enough travel left to
quite
> >cock the shutter. Generally the shutter would still function if you
could
> >cock it manually, but even then it feels pretty rough while the shutter
is
> >being cocked. Theres a steel toothed ring that bears on the aluminum
> >housing, and that's one of the main wear points. These shutters are on
> >either heavily used cameras, or have a lot of dirt in them.
>
>
> thanks for all the advice about this. I called the guy who repaired
> my rollei, and he said that he had checked it after adjustment and
> the shutter was working fine. I am beginning to believe that the
> reason I think the film is overexposed is that Ilford's HP5+ roll
> film is actually a very fast film, and shadow densities fall in the
> 0.7 range by design (by Ilford). I THINK my exposures are too dense,
> by inspection and by densitometer measurement, but Ilford wants them
> that way, so fine. Printing times will just be longer.
>
> By the way, you might find it amusing that Eudora thought that your
> message, quoted above, contained language that some might find
> offensive. ;-) Can't think what it might be: "corrosion"?
> "crack"? "rough"? In any event, there were two hot peppers next to
> it.
>
> --shannon
>
> >
> >----- Original Message -----
> >From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
> >To: <pure-silver@xxxxxxxxxxxxx>
> >Sent: Thursday, February 17, 2005 11:13 PM
> >Subject: [pure-silver] Re: old rollei over exposing
> >
> >
> >>
> >> ----- Original Message -----
> >> From: "Richard Urmonas" <rurmonas@xxxxxxxxxx>
> >> To: <pure-silver@xxxxxxxxxxxxx>
> >> Sent: Friday, February 18, 2005 7:59 AM
> >> Subject: [pure-silver] Re: old rollei over exposing
> >>
> >>
> >> > Quoting "Koch, Gerald" <gkoch02@xxxxxxxxxx>:
> >> >
> >> >> It
> >> >> is extremely important not to leave a shutter cocked for
> >> >> long periods of
> >> >> time.
> >> >
> >> > The manufacturers of the older leaf shutters generally
> >> > recommend
> >> > the shutter be left cocked. From a mechanical point of
> >> > view, the
> >> > cocked state will result in less chance of the shutter
> >> > misbehaving
> >> > (going sticky) as the driving spring is much stronger than
> >> > the return
> >> > spring, so there is more force available to 'break free'
> >> > any sticky parts.
> >> >
> >> > Richard
> >> > --
> >> > Richard Urmonas
> >>
> >>
> >> Well, I've never seen such a recommendation. If a spring
> >> is not tensioned beyond its elastic limit it probably
> >> doesn't matter if its tensioned or not as far as losing
> >> strength with time.
> >> Many shutters do work as you describe. When the shutter
> >> is cocked the restoring spring on the retarder winds the
> >> retarder to its starting position. This usually brings the
> >> speed control peg up against the speed cam. When the shutter
> >> is tripped the retarder is forced over by the full strength
> >> of the drive spring. If the retarder mechanism is glued
> >> together sufficiently by old lubricant it might just not
> >> move enough to allow the shutter to close again. Hard to
> >> know. I would not leave shutters with booster springs in
> >> their highest speed position because that puts a lot of
> >> force on some of the parts and I suspect the booster springs
> >> may be close their limit.
> >> Springs wear pretty much because of work hardening due to
> >> cycling rather than constant tension or compression.
> >> The Compur shuttes used in Hasselblads and the similar
> >> shutter used in EVS Rollei cameras was designed to be left
> >> cocked all the time, they must be in Hassy cameras.
> >>
> >> ---
> >> Richard Knoppow
> >> Los Angeles, CA, USA
> >> dickburk@xxxxxxxxxxxxx
> >>
> >>
>
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> >
> >
>
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