[alt-photo] Re: Alternative Exposure Unit (no pun intended)

[Alberto Novo]

Peter, 

> ... the gels I cut were from a "Lee 
> Filter"lighting gel swatch. Each swatch gel has 
> an attached chart of the transmission spectrum. It shows a transmission 
> graph going from 300 nm up to 800 nm. I made sure that I chose the gels 
> with a high degree of purity in their respective colour, and also that 
> they weren't transparent to UVA.

Have you a detailed figure of their UVA absorption? In the Lee Filters site 
I am not abe to find any technical documentation.
Most of the UV wavelength involving dichromate and ferric salts sensitivity 
is in the 350-400 mn range.
As for the Epson R2400 inks, I have published an analisys of their 
absorption in the UVA and visible absorption.
See http://www.albertonovo.it/scan/epson_inks.html 

Alberto 

Alberto