Re: Narrowing the slit on OLD pan cameras

[Alan & Shari Kafton <shmooze@xxxxxxxxx>]

Andy Buck wrote:
> 
> As I understand it, a narrower slit would limit the
> blurring effect of any lens distortion which, given
> the size and age of the lens, could be considerable.
> If I'm wrong, would someone pease correct me?
> 
> Andy
> 
> --- MMagid3005@xxxxxxx wrote:
> > Andy -- Why would narrowing the slit give sharper
> > negatives?  It would
> > increase the effective shutter speed, but if used on
> > a tripod it shouldn't
> > affect sharpness.  -- Marty
> >


Narrowing the slit CAN increase sharpness under certain circumstances. 
If the film is not perfectly synchonized to the focal length of the
lens, an effective "synchronization blurring" will occur.  If the slit
width is reduced in half, then this blurring will also be reduced by
half which increases the image sharpness.  Of course half the slit width
reduces your exposure time by a factor of two and makes your camera more
suseptible to banding if everything is not perfectly smooth....

--Alan Kafton