P3D Re: Filtered fluorescent lamps

[Duncan Waldron <J.Waldron@xxxxxxxxx>]

On Sun, 1 Mar 1998, Greg Wageman wrote:

> Assuming that *most* of the bleaching is occurring due to the presence
> of ultraviolet light, using a u-v filter *might* help slow the process
> down.  Slip-on UV filters for standard fluorescent tubes are available
> from Light Impressions (among others).
> 
> I'm hedging here, because I don't think all of the fading is due
> strictly to UV exposure.  Slides are known to fade in projection, and I
> don't think standard tungsten lamps emit a whole lot of UV.  So UV
> filtering may help, but probably won't completely eliminate fading.

Heat will also destabilize the image. As I recall, a temperature increase
of 18 degrees C will double the rate of a chemical reaction. This must be
a significant factor in image fade. By "standard tungsten", do you mean
non quartz-halogen? Quartz lamps do pour out a lot of UV.

Duncan W


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