This is a piece of stained glass which was exposed to the afternoon sun in a church steeple for about 80 years. Note that the glass at the edges did not color, as it was protected by the leading.

I made this mosaic with newer equipment than I had when the original series of three pictures was taken. See [id=14176125] and the two following it. The third picture in that series is darker than the glass.

So I cleaned the glass with oxalic acid solution and suspended it in front of one of Brian Riecker's light boxes. The first photo taken with my Nikon D70S was way too dark. Although I was using center-weighted metering, I was thinking that the relatively bright light at the edges of the picture caused the picture to be underexposed.

Then I took a series of six pictures at EVs of +1/3, +2/3, +1, +1.33, +1.67, and +2. Here they are. The color still is not quite right. Purple is apparently difficult to reproduce, and does not display correctly on my laptop computer's display because of its fluorescent back lighting. The actual luminance appears to be between pictures 2 and 3, but the hue is not quite right.

So I used the exposure correction facility in ACDSee to add a bit of red. I just "bent" the red curve upwards by a few percent. That did it. Apparently the set of bulbs in the light box are a bit short on red light. Of course, now the backgrounds have a red tint. But the hue of picture #3 is just about right on.

I'll try this again when I get my hands on a full spectrum light source.

There is a real art to all of this. Maybe it's time for one of Bob Alexander's CDs!