[Leica] Forscher's lights

[s.dimitrov at charter.net (slobodan Dimitrov)]

I remember doing that, only too well.
One reason why my ears are shot today, I never used ear plugs in those  
days.
S.d.


On Nov 17, 2009, at 6:46 AM, H. Ball Arche wrote:

> Back in the lith film/process camera days this was standard  
> procedure in shooting halftones; there was a bump, which was a brief  
> exposure of the film with out the overlaying dot screen, and the  
> flash, which usually came after the main exposure, and was exposed  
> through the dot screen. The idea was to punch up contrast.
>
> The flash lamp hung above the back of the camera, hooked to a timer,  
> and the exposure took place with the camera back dropped and the  
> film held in place on the vacuum back.
>
>
> ----- Original Message ----
> From: Lawrence Zeitlin <lrzeitlin at gmail.com>
> To: Leica LUG <lug at leica-users.org>
> Sent: Mon, November 16, 2009 5:24:34 PM
> Subject: [Leica] Forscher's lights
>
> Slobodan writes:
> "Didn't Forscher modify a Nikon with lights, in order irradiate the
>
> elmusion for low light shooting?"
>
> -------
>
> I don't know if Forscher was the first to do this but pre-exposure and
> latensification used to be old tricks of available light  
> photographers and
> cinematographers to eke out the last residue of sensitivity of films.
> Pre-exposure involved exposing the film to low light levels either  
> prior or
> after exposure. The idea was to get the image exposure over the toe  
> of the
> sensitivity curve. It effectively provided an increase in apparent
> sensitivity of 1/2 to a full stop. Latensification involved exposing  
> the
> film to mercury or ammonia vapors prior to exposure. It could also  
> gain a
> one stop increase in sensitivity. These techniques are rarely used  
> today in
> this era of ultra high speed films. You can find more about them by  
> looking
> through old photo books and magazines. The use of lights in cameras  
> was
> described in 1950s era magazines such as "35 MM Photography".
>
> One construction article suggested gluing 4 grain of wheat  
> incandescent
> bulbs on the inside of a Leica M camera near the corners of the  
> frame. The
> lights would be illuminated briefly by a battery switched on by the  
> flash
> contacts. The article suggested that this would work well with B&W  
> film but
> might give problems with color film because the lights would upset  
> the color
> balance of daylight emulsions.
>
> I never tried gluing bulbs to the inside of my camera but I did  
> experiment
> with pre-exposure and latensification. Both worked but there was too  
> much
> variability in the process and it proved to be far more trouble than  
> it was
> worth.
>
> Larry Z
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>
>
>
>
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information