80's tube ENG cams fun

[old_tv_nut]

Another thing about Plumbicons, Saticons, and such:

As the beam scanned the target, in almost all areas (except those pesky comet-tailing highlights), it had more than enough total current to discharge the target. This means that the charge would be neutralized by just the leading edge of the beam (a variable portion due to the varying charge level). So, the effective beam shape wasn't nice and symmetrical, but actually was a crescent shape. The beam was also partially discharging the next lower scan line, so the crescent was like an arc with the center toward the lower right and the pointy ends more up toward the right and down toward the bottom. This effect was called "beam sharpening," and resulted in the resolution for lines and edges slanted from lower left to upper right being better than for lines slanted the other way. A really fancy camera CCU would have a two-dimensional detail enhancer (using analog delay lines, or later, digital processing) that would allow independent adjustment of the detail sharpness for left-slanting and right-slanting lines.