[rollei_list] Re: 2.8FX shutter cock and film advance 'synchronisation'
- From: <chatanooga@xxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Wed, 14 Dec 2005 15:04:44 +0000
So,especially near the biginning of a roll, its possible to wind the film
only partially and still fire the shutte.....
Crikey -some sleuthing. This sounds exactly like my 'problem'. Will try
with my dud test roll to see if the 'cock-up' potential is less at higher
frame numbers as you sat..... FYI I did check the shortfall already by
writing on the film carrier and comparing positions (for the same frame)
between proper cranks and incomplet ones. On frame #4 I was about 1cm out...
On 12/14/05, Richard Knoppow <dickburk@xxxxxxxxxxxxx> wrote:
>
>
> ----- Original Message -----
> From: <chatanooga@xxxxxxxxx>
> To: <rollei_list@xxxxxxxxxxxxx>
> Sent: Monday, December 12, 2005 6:56 AM
> Subject: [rollei_list] Re: 2.8FX shutter cock and film
> advance 'synchronisation'
>
>
> thanks carlos. The behaviour as you describe is definitely
> how it should be
> - ie foolproof. Shucks!
>
> I just made a test on an MX Automat using a dummy spool
> and card to fool the film feeler. The crank stroke needed to
> cock the shutter is quite short compared to the stroke
> needed to wind film at the beginning of the roll, about
> enough to get the crank pointing straight forward. The
> shutter is locked out until the crank is returned to its
> neutral position but once there the shutter will fire.
> Because of the metering arrangement the crank stroke varies
> throughout the roll, becoming shorter as more film is wound
> up on the take up spool. So, its necessary that the shutter
> cocking function be complete with a little less than the
> minimum crank stroke ever needed for winding film. So,
> especially near the biginning of a roll, its possible to
> wind the film only partially and still fire the shutter and
> move the counter. The crank must be moved to the limit of
> its movement for each frame. I didn't measure how much film
> is moved when the crank is moved just enough to cock the
> shutter but it may be short enough to cause overlaped
> frames, at least in some parts of the roll.
> A way of checking this is to sacrifice a roll of film to
> use as a test tool. In older Rolleis its possible to fool
> the camera that the back is closed when a button or lever
> actuated by the back is held in. Once this is done one can
> observe the winding and mark the frames with a pencil to
> check the amount of movement. I suggest doing this before
> sending the camera off to be serviced to make sure there
> actually is a problem and that your camera works the same
> way as the one I checked.
>
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@xxxxxxxxxxxxx
>
> ---
> Rollei List
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