Re: [Leica] Early Summitar

["Robert E. Welsh" <rwelsh@craftech.com>]

I used to use the same green safelight techique. It worked well -and could be
done either before or after with the same effect. Obviously, after was better
since you just loaded it into your developing tank reel after 'flashing'   Bob

Dan Post wrote:

> Walter-
> Your story brought back memories- the idea of flashing film . The theory
> behind that is that film has a threshold at the toe- no density at all until
> that point is reached- I believe it is called the 'Speed Point' because the
> amount of light to attain that point on the 'toe of the DlogE curve
> determined the film speed. If you gave the film just enough exposure to get
> it to reach that 'speed point' then any additional exposure would help bring
> up the shadow detail! Tricky business- we used a dark green safelight at
> about 4 feet for a few seconds- then re-spooled it!
>  We used to 'flash our Tri-X when I was in high school so we could
> photograph the night football games with the flashes we had available in
> 1965! We also tried fuming the film in ammonia fumes to make it more
> sensitive, but that didn't work out too well.
> It's refreshing to know we weren't totally out in left field then!
> Dan
> dwpost@msn.com