Re: Darkloading

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

On 12 Aug 96 at 3:44, George L Smyth wrote:

> Willem-Jan Markerink wrote:
> > 
> > Mmm....but given the fact that the line is steep on a *log*
> > chart, and hits the 0 log mark....doesn't that imply that it runs
> > down *VERY* steep and definately to 0 when speaking in % of maximum
> > sensitivity?
> > I thought those log charts were ment just for that: reading the
> > behaviour around 0, the log behaving as an 'exploded view' of the
> > Y-axis the more it goes to 0.
> > 
> 
> But there's the rub:  is this a log chart?  And what do the markings
> represent?  Until these questions are answered, neither of us has room
> to argue.  Yes, running our won tests is really the only way to go.  Got
> a densitometer? <g>

Ooops!
My only reference for this is an article in FotoMagazin (8/95), and 
it definately shows a log chart. It reads "Log sensitivity in 
ergs/cm^2" on the Y-axis. The blue area of Konica peaks at 1.25 
ergs/cm^2, the red area at a little more. The blue peak of Konica is 
almost equal to that of the Ilford FP4 plus; and the red peak of the 
Konica is almost equal to the sensitivity of the Kodak HIE in that 
area (HIE only climbs another 0.25 ergs/cm^2 towards IR).
  
I am sure someone can give a meaning to ergs/cm^2....I can't....8-))

And no, I do not have a densitometer; my current IR-gear project is a 
Zeiss monochrometer, to analyse filters. But I guess with some 
additional effort, it can also work as an adjustable monochromatic light 
source to analyse spectral sensitivity of film. And I am sure someone 
on the list would want to volunteer to do some density readings....;-)) 

--
Bye,

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The difference 
between men and boys
is the price of their toys

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

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Topic No. 7