Much of the second act of Aaron Sorkin's play The Farnsworth Invention revolves around Philo Farnsworth's supposed inability to find solutions for the low-light sensitivity of his Image Dissector tube. This interpretation is very much the "RCA version" of the early pre-history of television — that Farnsworth's Image Dissector was a fatally flawed device, and that television could only be commercialized after the principal of "light storage" was introduced in Vladimir Zworykin's Iconoscope.
When I met Aaron in San Diego in the spring of 2007, I showed him an Image Orthicon tube — the tube that really made television practical in the 1940s and 50s — and tried to explain to him how much of the art in that device — art that effectively solved the "light problem" — was traceable to Farnsworth patents.
Now comes a letter from another reserarcher / historian with an engineering background, one Eduardo Zeron, who validates what I've been saying about the origins of the Image Orthicon. He also takes issue with some of the points in my old "Who Invented What and When" essay, which points I am happy to see corrected.
But those corrections don't undermine the important assertion, that Farnsworth had his own solutions to the "light problem," that those solutions found their way into the technologies that made television popular, and that the historical interpretation in The Farnsworth Invention is what is fatally flawed here, not the invention itself (nor the inventor).
Mr. Zeron's letter:
Dear Paul Schatzkin.
I really enjoyed your Farnovision chronicles web page, especially the Part 10 where you point out the historical importance of Farnsworth's U.S. patent 2,087,683, and how Sarnoff needed to buy it (for $1 million) in order to sell his Image Orthicon.
Farnsworth invented both the Orthicon and the "scanning with low speed electrons" in his U.S. patent 2,087,683 (filed on April 26, 1933, and granted on July 20, 1937). The only difference between the Farnsworth Orthicon and the RCA one is the fact Farnsworth projected the optical image and did the scanning in the same side of the target plate, while RCA projected the optical image and did the scanning at the opposite sides of the target.