Have you ever heard of isochromatic film? Yeah, me neither! I found a definition, with background, below...
Have you ever heard of isochromatic film? Yeah, me neither! I found a definition, with background, below...
In 1873, Hermann Wilhelm Vogel discovered that the spectral sensitivity could be extended to green and yellow light by adding very small quantities of certain dyes to the emulsion. The instability of early sensitizing dyes and their tendency to rapidly cause fogging initially confined their use to the laboratory, but in 1883 the first commercially dye-sensitized plates appeared on the market. These early products, described as isochromatic or orthochromatic depending on the manufacturer, made possible a more accurate rendering of colored subject matter into a black-and-white image. Because they were still disproportionately sensitive to blue, the use of a yellow filter and a consequently longer exposure time were required to take full advantage of their extended sensitivity.
https://en.wikipedia.org/wiki/Photographic_film
In 1873, Hermann Wilhelm Vogel discovered that the spectral sensitivity could be extended to green and yellow light by adding very small quantities of certain dyes to the emulsion. The instability of early sensitizing dyes and their tendency to rapidly cause fogging initially confined their use to the laboratory, but in 1883 the first commercially dye-sensitized plates appeared on the market. These early products, described as isochromatic or orthochromatic depending on the manufacturer, made possible a more accurate rendering of colored subject matter into a black-and-white image. Because they were still disproportionately sensitive to blue, the use of a yellow filter and a consequently longer exposure time were required to take full advantage of their extended sensitivity.
https://en.wikipedia.org/wiki/Photographic_film
Oshi, I've been meaning to ask you something,..remember the channel or group that we used to go to, that was all about the 60's 70's 80's ? Has it been taken down or something ? I cant find it in my groups or anywhere. If you have any info on this, please let me know, if you don't mind. Many thanks my friend. :-) Oshi Shikigami
ReplyDeleteThere are the old ons and some new ones. I will try and find links for you. I see postings, almost every day...
ReplyDeleteOshi Shikigami ...thanks Oshi. I was left with that community by an Italian man, if I remember right,.but I gave it to a man from California, by the name of Johnny something. The reason that I wanted to know is because I'm constantly running across photos and material, that would go real good with that community. Thanks a bunch my friend. :-)
ReplyDeleteI am trying to find it. However G+ does not want to list all of my communities, just a sampling. :-( If I find it, I will share.)
ReplyDeleteThe Vintage Life
ReplyDeleteOshi Shikigami ..not the Vintage Life,..no, not that one. I guess the one I was talking about has been ditched. Thanks for looking it up for me Oshi. :-)
ReplyDelete