Re: Test on Kodak EIR film

["Willem-Jan Markerink" <w.j.markerink@xxxxx>]

On 27 Oct 98 at 11:51, Helmut Faugel TE wrote:

> 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.

CC20B?
I only know Y(ellow), M(agenta) and C(yan).
Even if you mean cyan, it would be opposite of what Symon 
expirienced....a red shift at short exposures, or a blue shift on 
short. This is also what made me ponder about adding a strong ND 
filter to decrease the red tones....ie a blue shift because of long 
exposures....
  
> > 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.

Mmm....those are glass....my assumption of metal particles is based 
on resin filters....might be a different process and use of 
dyes/particles.
 
> 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 ;-)

50mm rain tonight....yahoo!....8-))
Remember: what falls down here, can't fall down in Germany anymore,
not with a west-wind....;-))
Until now 1000mm of rain, with a normal year average of 760nm....

Willem (but it keeps the EIR/HIE expenses down) Jan






 

--                 
Bye,

Willem-Jan Markerink


      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]
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