... perhaps KevH can shed some light !! on the reason for the change of colour.
Err, well ... nope! I can only comment on what I see, and what little I may know about the glass batch, not why
it happens. Even with some technical data about UV reactions I can't honestly say why the various colours are seen. Apparently it's all down to "absoption", "reflection", "refraction" and other long words that I don't undertsand too well.
Fluorescent light has a strong yellow/green element, one of the hardest to compensate for in photography ...
Yeah, tell me about it :!: I now have a couple of excellent "table-top" studio lamps, each with 12 inch reflectors and containing 3 x 30W "daylight rated" fluorescent bulbs (actual rating 6,400 degrees Kelvin). Along with good diffusors and a "shooting cocoon", I can now get superb results for paperweights ... as long as they don't have much clear glass in the photo view.
Any clear glass shows with a mild green tint, even when the camera (an expensive semi-pro digital) is set to any of its various compensations for white balance etc. I have also tried loads of adjustments in the photo editing software [I use Photoshop Elements] but nothing will do the job properly (at least, not to my satisfaction). The closest I have got to a correction, which gives something aproximating to a grey tone, is a setting of "Flourescent +4" in the camera's "pre-set white balance" range, but I cannot find out what that actually means.
Anyone actually know which type of filter can correct the fluorescent yellow-green tint?