On the boxes of the new films there is no hint to this technology any more.
I can confirm what Gerhard Popp said, having been myself, involved in the work on green spectral sensitization and coating of negative films. Although he was not head of that division when I was in it, we were working with that problem many years ago and found it to be quite correctable without an extra layer.
However, some Kodak films did have what was essentially an extra layer in the sense that the fast and slow components of the C and M layer were coated in separate operations to improve speed and grain.
Fuji was constrained from some of these approaches due to existing Kodak and Agfa patents.
thanks for the additional information, very interesting.
IDK the specific patents, but knowing the approximate dates were in the 80s, I would assume they are expired now.
Kodak Ektapress 1600 (Gold II?) gave natural results with sodium vapor lighting, fluorescent illumination and also compact fluorescent lamps, as my recent scans of negatives from 1996 have shown. It is a pity that this film has been discontinued.
The new Fujicolor films give essentially the same results with such light sources as the earlier 4-layer types. But I assume that of the 4th-layer technology, initially integrated into Reala 100, the patent has expired now.
hmm, i have a lot of rolls of Superia XTRA 800 (4th layer tech), works great exposed @ 640.
Very interesting. Now, what about Fuji Super HG 200? I always assumed it was the same as Superia, but it's all I can ever find locally.
So can someone point out this extra layer they call/called "4th layer"? I don't see the difference in the structure they list on data sheets from one to the other.http://i49.photobucket.com/albums/f2...g?t=1246031878
So the gist of this, is that the 4th layer, solved some problems with the existing chemistry, and was used as an interim solution whilst the emulsion chemistry improved to a point that this layer was redundant.
Sounds like a plan to me