[photo-3d] Re: Film slippage in RBT mounts

["John Goodman" <jgood@xxxxxxxx>]

Paul Talbot wrote:

> Variability in the snugness of fit of RBT pin bars in the
> mount channels has been mentioned on photo-3d before.  
<...>
> I recently read someone mention always taping down the RBT
> pin bars.

Some time ago I mentioned using needlenose pliers to squeeze 
the spots (right over the pair of holes that indicate orientation) 
to slightly broaden the white pinbar plastic at the points that 
actually touch the insides of the tracks they slide in. I want my 
pinbars nice and tight, so there'd be essentially no chance of 
chips slipping.

Now, I just bend ones that are too loose for my tastes. I bend 
them into a slight "U", with the curve oriented up or down (plus 
or minus along the Y-axis), but away from the window where 
the edge of the track groove is narrowest. The pinbar plastic is 
a type that doesn't want to bend (they break if too much force 
is applied). The stress in the plastic is noticeable as a white 
discoloration and loss of translucency, but this doesn't affect 
their function at all. Even completely loose ones, after bending, 
have a nice, snug, sliding fit.

I find the gray, alternate pinbars are often extremely tight in 
the tracks, to the point of causing fingernail pain after a bout of 
mounting. Since I reuse mounts, the above bending trick 
especially comes in handy when using a normal pinbar in a 
track where a gray one was.

jeg