[alt-photo] Re: UV Processing units

[Peter Friderichsen]

I did some basic tests exposing light through coloured filters. (I 
mentioned this in an earlier post) I did find that the cyanotype 
using ferric ammonium citrate/potassium ferricyanide was slightly 
sensitive under the blue light. I did however read that the iron 
oxalate salts are fairly sensitive up to 500 nm so perhaps some of 
the iron salts will work while others may not work so well. Mike Ware 
mentions this sensitivity of the oxalate salts in his book on Cyanotypes.

I am looking forward to see what the results on this will be.


At 03:17 PM 03/13/2010, you wrote:
>Good luck Andy.
>
>Which UV leds did you purchase? The UV leds mentioned in the article
>are defined as being 395nm, albeit being UV by definition (<400nm),
>aren't much close to what we get from conventional lightsources.
>(Something like 360nm.) You unit could work for dichromate processes
>but you may experience difficulties (slow printing speed) with iron
>processes... ??? Hope it goes well for you.
>
>2010/3/13 Andy Schmitt <awschmitt at verizon.net>:
> >
> > Hi all
> > While perusing "Instructables" I ran across a few references to people
> > making Printed Circuit boards with an exposure unit made of UV LED's. This
> > peaked my curiosity & I went & purchased 400 UV LED's, resistors, etc & am
> > slowly soldering together an exposure unit...If I ever get 
> through it I will
> > post back.
> > In case someone wants to steal my thunder & do it themselves [ 8o)) ]
> > Go to www.instructables.com & look up:
> > How to make a printed circuit board (PCB) using the UV light LED method.
> > by JoeyJunior on July 5, 2009
> > (If you do, you need to tell us how it all comes out)
> > ...
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