29-11-2020, 11:40 AM
(This post was last modified: 29-11-2020, 11:41 AM by peter scott.)
I think the mosaic was divided into very tiny globules such that the scanning spot would cover a large number at any point on its scan.
I think the limiting factors on resolution were the evenness of electron beam focus, TX & RX and the overall vision system bandwidth from camera to receiver.
Optical depth of focus was certainly small with the original Emitron cameras, perhaps just a few inches in normal studio use.
The first Emitron cameras used a 6.5" lens. This is approximately equivalent in 35 mm camera terms to a focal length of 47 mm. The lens had an f3 full aperture and if focussed 3 feet away would have a rather limited depth of focus of approximately 4". If you stopped the lens down to get 6" the illumination would need to be quadrupled which would generally be unacceptable to the subject. The substantially shorter focal lengths possible with the Super Emitron greatly improved things.
The tilt and bend shading was certainly a big factor in picture quality especially in film transmission where the producer was not inspecting the next scene before a camera change.
Peter
I think the limiting factors on resolution were the evenness of electron beam focus, TX & RX and the overall vision system bandwidth from camera to receiver.
Optical depth of focus was certainly small with the original Emitron cameras, perhaps just a few inches in normal studio use.
The first Emitron cameras used a 6.5" lens. This is approximately equivalent in 35 mm camera terms to a focal length of 47 mm. The lens had an f3 full aperture and if focussed 3 feet away would have a rather limited depth of focus of approximately 4". If you stopped the lens down to get 6" the illumination would need to be quadrupled which would generally be unacceptable to the subject. The substantially shorter focal lengths possible with the Super Emitron greatly improved things.
The tilt and bend shading was certainly a big factor in picture quality especially in film transmission where the producer was not inspecting the next scene before a camera change.
Peter
