Re: Test on Kodak EIR film

[Helmut Faugel TE <htf@xxxxxxxxxx>]

On Mon, 26 Oct 1998, Willem-Jan Markerink wrote:
> On 25 Oct 98 at 20:36, Symon K.W. Wong wrote:
> 
> > Can anybody explain to me the phenomenon described as follows :
> > 
> > It's a test on Kodak EIR film by shooting at 2 seashore scenes at about 
> > 11:00 am. I made 10 shots per scene with 5 in one exposure set while 5 
> > in another equivalent set. All shots for one scene were taken almost at 
> > the same time (+/- 1 min. between the first 5 and the subseq. 5).
> 
> I recall that Helmut Faugel has done some Schwarzschild testing, and 
> concluded that (infra?)red sensitivity drops quite significantly with 
> longer exposures. 1/500s vs 1/15s might be enough to trigger this 
> effect....

EIR does not need any compensation between 1/1000s und 1/100s, but
at 1/10s it needs +1 stop and a CC20B filter according to the
data sheet, or in other words it shows a strong color shift at
exposure times you do not even think of reciprocity failure.
 
> This triggered also another idea: to decrease the extreme red tones
> with E-6 development, one could add a dense ND filter....problem is
> that ordinary ND filters don't block IR, so you would effectively
> block all visible, including red, but not infrared.

Right!

> OTOH, I believe
> that the very dense ND filters contain metal particles to achieve
> this density in the first place, instead of organic dyes....and
> metal blocks IR just as good.

Sometimes I use a B+W 113 (ND 4.0, eats up 13 1/3 stops) and this 
cause a strong red cast on my color slides, even on films that are 
not sensitive to reciprocity failure and color shift (Sensia 100 II,
EliteChrome 100 & 200). I've got a call from B+W after I asked them
at a photo fair about this problem and the answer was that this
filter shows 2% transmission at 800nm, this is only ND 1.7 instead
of ND 4.0 at 550 nm.

What I could do is running a Test using my Thousend Oaks ND 4 filter
which consosts of a thin metalfilm on glass, but at first Willem-Jan
has to keep all the bad weather away from germany ;-)


-- 
Helmut Faugel 
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