I'm trying to create a lit surface similar to a backlight for an LCD display (I'm replacing an EL panel in an arcade machine). For various reasons I don't want to just replace the EL with more EL.
The biggest constraint is that I only have about 0.2 inch of thickness to work with (the old EL panel and it's PCB are slipped into a very narrow space).
My thought has been to edge-light an acrylic panel (I have some very narrow LEDs from LITE-ON), and then etch it's surface somehow so that the light will exit from the face of the panel. My problem is that I don't have a good way to measure the light output to see if one of my ideas is better than another.
Is there some simple trick I could do with a digital camera to get an idea of the light output of the panel? I don't really need an absolute measurement, I just need some way to compare relative to my other attempts.
Also, any clues on an optimal pattern for etching the acrylic would be nice - I've so far tried scratching the emitter surface with steel wool and sandpaper to not great effect. I also tried scoring parallel lines with a knife, and that's been interesting, but I'm having trouble figuring out what's my best bet here.
Should I be trying for good light output from the acrylic then adding a diffuser on top of that?