Eric, you say a real benefit for BL bulbs from the Starphire. I realize
your experience is with pt/pd, but I'm curious if the benefit would be
mostly in speed, or in "the curve." I imagine if the curve is affected it
would not be the same effect in different media, but wonder if you would
hazard a guess on any of the above. (I have the sheet I removed from the
NuArc because it made gums worse... might try it with the BLs. But isn't
worth it for speed because gum exposure there is only 1 to 3 minutes to
begin with.)
Thanks,
Judy
On Fri, 3 Dec 1999, Eric Neilsen wrote:
> Michael, I use and recommend the Starphire glass from PP&G. In my smaller
> frames, 16x20 and smaller, I use the 4mm thickness. I also use a 8mm sheet
> for some special applications. As Jeffrey pointed out, stay away from
> single pane unless you have a very cooperative source that will let you
> reject any that shows imperfections. The Starphire allows a greater amount
> of UV than does the standard green. It is however, more pronounced at the
> 370nm to 300nm range. The output of your light will certainly influence
> your choice or should. If you use BLB the peak at 350 to 360, and closer to
> where it may not really matter if you use Starphire or Standard. And
> further, if you use the Super Actinic, peak about 415nm, it may not matter
> at all since at that level they both pass nearly equal amounts.
>
> I would say that if you go with BL's than you will see a real benefit to
> Starphire, if not stay with standard.
>
> Happy printing
>
> EJ Neilsen
>
>
>
> Michael Mutmansky wrote:
>
> > Hello all,
> >
> > I am building a darkroom for PT/PD printing, so I am new to the
> > alternative process realm, as well as this forum. I have a question that
> > I didn't see an answer for in the archives.
> >
> > I believe most people use "normal" glass in printing frames for
> > platinum/palladium printing. This may not be the best choice, since
> > normal glass starts to block UV light at about 300 nm or so, and is only
> > about 75% transmissive through the UVA range. Is there any point to
> > trying to find a special glazing? If so, what would the glazing be
> > (quartz ?)?
> >
> > I am a specifier in the building industry, so my knowledge of glazing
> > transmissivity is being applied here, and possibly I am making a bigger
> > deal of this than it needs to be.
> >
> > As it stands, I have the spectral distribution curves for several of the
> > blacklight lamps, (350BL and BLB) and there is not much emission above
> > 300nm, but I would think a more UV transparent glazing will definately
> > reduce exposure times...
> >
> > ---Michael
>
> --
> Eric J. Neilsen
> 4101 Commerce Street, Suite #9
> Dallas, TX 75226
> 214-827-8301
> http://home.att.net/~e.neilsen
>
>
>
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