Happy to report a discovery of sorts as a result of the research led by [USER=16321]Deancfh[/USER] on the chest lights. The correct vintage 7-segment display I sent him had some unique properties which very neatly explain all the remaining unexplained weirdness we see of the chest lights in the film and production photos -- mainly regarding the range of brightnesses of the display segments.
Below you can see how the displays are not lit the same brightness. We know now thanks to Dean's research, the 88888 freeze is likely the result of the battery running low. But that didn't really explain the different brightnesses, especially the large differences between the second and fourth digits.
[ATTACH=full]237888[/ATTACH]
We can now safely say the reason is the design of the displays themselves. They are quite different than anything available today or even shortly after the late 70's. To put it bluntly, they're a pretty crappy design.
Below is a typical 7 segment display and how they look when lit:
[ATTACH=full]237889[/ATTACH]
This is the correct vintage type:
[ATTACH=full]237890[/ATTACH]
Look how uneven the bars are lit. Right away we can see why these displays look uneven on the originals. Each segment has only one tiny bulb which isn't diffused enough to light the whole segment properly.
Then something really cool happened. Not only were they looking dim and uneven, the effect can be compounded when multiple displays are added. In the pic below, the 'U' is the vintage display. Notice how the bottom of the U is so much dimmer here after another display is added:
[ATTACH=full]237891[/ATTACH]
Look familiar?
[ATTACH=full]237900[/ATTACH]
These displays are terrible. But from day one I wanted my display to look like scene 371, as in the first pic with the frozen 88888 and a terribly unevenly lit display. I had a plan all along to get that look with tricks, but we don't need tricks anymore. We know how it was done, thanks to Dean. However, right now we are speculating maybe for the ESB, that fourth bright digit was maybe another manufacturer version thrown in by happenstance. We don't know for sure. The answer may come from getting a complete set of the those rare vintage 7 segment displays and wiring them up.
And also... this...
[ATTACH=full]237893[/ATTACH]
What are those you ask? Correct vintage bar displays that go above the digits. This is what the correct ones look like. Will be interesting to see how these things look when lit up.
