@gewubs, would you mind sharing your setting in a “Beyond the Manual” post linked to this one please? This looks like a rather promising technique.
Gotta love fabulous unintended results!
I read through the comments but I may have missed it if anybody suggested this already.
For a backlight - you can find “cheap” used or broken old tablets and phones on ebay that you can hack apart. Behind the screen will be a light element (sometimes a bar, sometimes many little LEDS) and several layers of fresnel lenses. You could take out that portion and keep the light on with some tinkering.
Alternatively - there are backlit photo frames out there… on second thought, that might be easier.
Really awesome though, I love it and I’m gonna steal it!