Moderators: Dave Moll, Steve Anderson
Klaas Robers wrote:It is not impossible that Baird made the first one. However there were others that only could make "shadow" images, purely black and white. Baird was defintely the first that made grey scale pictures. The problem was colour sensitivity and gamma.
The first photo cells were most sensitive in the blue colours. If you illuminate a face (that is were it is meant for) with blue light, or which is the same, use a blue sensitive photo cell, then you get almost unrecognizable faces. The same is with infra red sensitive photo cells and/or infra red light. No, it was not that easy in those days...
Klaas Robers wrote:That is what I said: only shadow images, no grey scale reproduction. The same is with a French man. You want to see the face of a person with more or less natural grey shades. That is where J.L. Baird was hunting after. J.L. demonstrated this in 1926 in a store in London. However nobody has photographed what was visible. But there are photo's of a crowd waiting to get a viewing place.
And then still there were the problems with the wrong type of light and the photo cells.
Klaas Robers wrote:You may assume that Paul Nipkow made himself something of an aperture "image dissector". Crude amplification was already possible by a combined device of a telephone receiver and a telephone microphone. And there were already fast and sensitive relays, that could give on-off signals. Who knows what Paul has done in those days around 1880. So Jenkins was not the first one, neither Baird, that experimented with the disc, lens or aperture.
It was already in 1850 that a telefax was demonstrated, but this was seen as picture telegraph. This was only on-off, black and white. That must be the reason that Jenkins experimented with this, a very fast picture telegraph. And it is also not impossible that Paul Nipkow had this in mind when he started some disc experiments. However in his patent he wrote nothing about on-off modulation. That is not unusual, write a patent as broad as possible.
bananaya wrote:Hi there, has anyone here ever come across any concrete evidence to suggest that Australian, Henry Sutton, was able to build the telephane (circa 1890)? I know he definitely devised a method, his designs of which appear in a number of journals, however was he able to build one and successfully transmit an image using that technology (Nipkow disc; Kerr Cell) at the time? Thank you in advance!
Users browsing this forum: No registered users and 31 guests