Histograms in photo displays, when did it start? Options

[dvandorn]

I know that by the time the Voyager Jupiter encounters began, images coming in "hot off the wire," so to speak, were displayed (on TV, anyway) with histograms alongside the images.

Was this when the practice of showing histograms along with the images began? If not, when did the practice start? I don't recall seeing them on Mariner 6/7 images, or on Mariner 9 images. Were there histograms on the initial public release images from Mariner 10, or either Pioneer 10 or 11? (I have my doubts about the Pioneers, as they had a scanning photomultiplier tube in lieu of a real camera.)

And note that you don't see it much anymore -- when did the practice stop? Or was it really mostly done just during the Voyager encounters?

Anyone remember?

-the other Doug