CompuServe Messages

Ken, > What would be the limitation on the archive life of a Photo-CD – do the dyes "fade"? The only dyes that affect data on the Photo CD disc are the dyes into which the data are written. Under the wrong circumstances (such as extended direct sunlight) I imagine they do fade. However, we have selected extremely stable dyes. We are continuing our testing and don't have quantitative detail to publish yet. Our current official position is that the discs and data will last "at least as long as a color photograph or negative." The storage conditions for maximum keeping are similar: low temperature, low ambient light, and low humidity. One interesting point about digital storage is that an intact disc can be copied without any data loss. So if you keep it in good condition for, say, 50 years, and copy it, you start the clock ticking again. With color photographic materials, fading takes place gradually and not consistently between dye layers. So although the image might be in pretty good shape in 50 years, the process of copying it will loose some quality, and any dye-degradation will be copied in the process. Regards … Paul