UV nanometer

[waynecrider]

What's the nanometer rating for UV bulbs for alt printing. I ask as I see that Aristo Grid has 351nm bulb replacements for Graflarger's. Would these be bulbs for specialty priinting purposes outside alt requirements?

 

[nworth]

It varies somewhat depending on the phosphor, the mercury pressure, and the glass, but generally there is really significant light from about 310 nm to about 500 nm. The peak is around 350 or 360 nm, and glass and gelatin absorb most of the light shorter than about 345 nm. The bulbs match the spectral sensitivity of Azo paper pretty closely, except that they extend more into the green.

 

[Joe Lipka]

Sandy King did a lot of research on this. Results I think were published at Ed Buffaloe's Unblinking eye web site.

 

[waynecrider]

For anyone who cares to read Sandy King's article: http://unblinkingeye.com/Articles/Light/light.html

 

[waynecrider]

It varies somewhat depending on the phosphor, the mercury pressure, and the glass, but generally there is really significant light from about 310 nm to about 500 nm. The peak is around 350 or 360 nm, and glass and gelatin absorb most of the light shorter than about 345 nm. The bulbs match the spectral sensitivity of Azo paper pretty closely, except that they extend more into the green.

So a 351nm bulb in a Graflarger would be a optimum light source for Azo contact printing. Funny that Aristo would offer such a bulb for a Graflarger?

Besides the UV bulb, they have other Graflarger bulb options if anyone is interested.