Talk:Wirephoto

Latest comment: 1 year ago by Jpgordon in topic Expansion source

Is there any info one could add about how these were transpmitted? Printed photos are halftone screened, i.e., broken into little dots with B/W or color values, so were wirephotos transmitted digitally?

I ask because sending the dots digitally seems to make sense, because the dots would have discrete values. I'm therefore having a hard time envisioning that these were transmitted via analog. But digital transmission in the 1920s also doesn't make sense to me either. --Spiff666 (talk) 15:49, 9 July 2009 (UTC)Reply

The BARTLANE system invented in 1920 was digital. Most systems of the early 20th century were analog. Dicklyon (talk) 15:52, 9 July 2009 (UTC)Reply
We should add something about Arthur Korn's 1907 system. Read abokut it in the NYT. It says via telegraph, but I don't think it was digital. Dicklyon (talk) 15:57, 9 July 2009 (UTC)Reply

I suggest adding this 1937 educational film to the references, it explains the process in great detail (not digital at all, as you will see): http://archive.org/details/SpotNews1937?start=0.5 — Preceding unsigned comment added by Gebseng (talkcontribs) 12:35, 10 August 2013 (UTC)Reply

Belinograph

edit

Actually, Belin's original phototelegraph did not use a photocell to analyse its original document. It relied instead, as the American Noah S. Amstutz' machine had (1895), on the relief obtained by dissolution of the unexposed part of bichromated gelatin in a photograph. In Germany, Dr. Korn's rival aparatus did rely on selenium cells. These cells have a slow settling time, so Korn had to use a clever differential system. Conversely, to use Belin's machine, one had to make a special print of the photograph. I do not know at what point Belin turned to photocells. May be that's after tube sensors were made available. PolBr (talk) 13:41, 7 January 2014 (UTC)Reply

Expansion source

edit

Anyone interested in expanding this article will find this history of UPI Newspictures useful. --jpgordon𝄢𝄆𝄐𝄇 16:51, 26 January 2023 (UTC)Reply