Re: IR- screw Leica rangefinder option? Don't know yet...

[boblong@xxxxxxxxxxx (Robert Long)]

On Tue, 27 Aug 1996 09:55:51 +0100, you wrote:

|I guess Joe ment that since darkloading is near impossible, EI is 
|the only sane alternative.

IR Ektachrome can be loaded in subdued light, instead of total
darkness, then?  I had forgotten.

|Btw 1: you can use opaque IR filters with EI, but you end up with an 
|overall red image; red in those parts where HIE would be bright white 
|when using the same filter.

That's what I meant by losing the full color spectrum of the film.  I
don't see any point in it.

|Btw 2: the recommended minus-blue *is* an ordinary yellow filter,
|Kodak recommends #12, but I wasted an entire film with it; I have
|used a b&w orange #21 from Cokin, and was very satisfied with
|results. Inbetween there is also a color #16. 

First, according to Kodak's spectrographs, a No. 12 has an extremely
sharp cutoff at 500 nm, whereas the other yellow filters (8,
medium-yellow, K2; 9, deep-yellow, K3) are less sharp and include some
shorter wavelengths.  When I've tried these filters or orange (Wratten
21?), I've consistently found the color to be similar but not as clear
and clean and vibrant.  I therefore stopped using anything but a
Wratten 12 with the material.  I don't understand how you could have
"wasted an entire film with one."  But I haven't used the material in
at least ten years, so maybe it has changed?  Not likely.



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Topic No. 3