RE: BL vs BLB tubes for cyanotype

Sandy, I wanted to make sure that you understand that when I say " my data"
,I am not talking about the web site or data that I produced, but a spectral
data sheet issued by PPG back in 1992 that has the data that you so
carefully retrieved as I posted it back in 1999.

Eric Neilsen Photography
4101 Commerce Street
Suite 9
Dallas, TX 75226
http://e.neilsen.home.att.net
http://ericneilsenphotography.com
 
> -----Original Message-----
> From: Sandy King [mailto:sanking@clemson.edu]
> Sent: Wednesday, November 16, 2005 8:51 PM
> To: alt-photo-process-l@sask.usask.ca
> Subject: RE: BL vs BLB tubes for cyanotype
>
> I went to the site and looked at the .pdf file, but I did not see
> anything there at all about UV transmission at specific nanometer
> range.
>
> Let me know what you find out from PG&G.
>
> Sandy
>
>
> >I am back. The web site you link to is PG&O. The transmission data is
> indeed
> >quite different and looks more like Solarphire than Starphire. My data
> has
> >the PP&G logo.
> >
> >Below is a link to PPG and their Starphire Glass
> >
> >http://corporateportal.ppg.com/NR/rdonlyres/F736A32E-E981-4292-A954-
> C4206B0F
> >EE97/0/starphire.pdf
> >
> >
> >Eric Neilsen Photography
> >4101 Commerce Street
> >Suite 9
> >Dallas, TX 75226
> >http://e.neilsen.home.att.net
> >http://ericneilsenphotography.com
> >
> >
> >> -----Original Message-----
> >> From: Sandy King [mailto:sanking@clemson.edu]
> >> Sent: Wednesday, November 16, 2005 6:22 PM
> >> To: alt-photo-process-l@sask.usask.ca
> >> Subject: RE: BL vs BLB tubes for cyanotype
> >>
> >> Eric,
> >>
> >> I am puzzled by some statement you have made about Starphire. In your
> >> messages of today you have suggested that Starphire glass transmits a
> >> significant percentage of radiation below 350 nm. And you have been
> >> saying this for a very long time. For example, in a message to the
> >> alt-photo-list back in December of 1999 you wrote, and I cite the
> >> message:
> >>
> >> On Sat, 4 Dec 1999, Eric Neilsen wrote:
> >>
> >> OK , I found my charts. Starphire transmits 35.5 % of UV light @
> >> 300nm where Standard transmits .3%; @310nm 53.1% Star and .8%
> >> Standard; @320nm 67.9% Star and 9.1% Standard,; @330nm 79.2% Star and
> >> 34.4% Standard; @340 86.1% Star and 61% Standard; @350nm 89.1% and
> >> 77% . At 360nm and above it stays at about 91% for Starphire and 86%
> >> for
> >> Standard.
> >>
> >> Contrast your information with the specifications in this link,,
> >> http://www.pgo.com/pdf/ppg_starphire.pdf, which gives the following
> >> figures. Unless I am missing something terribly obvious, your figures
> >> are very different from those at this source, which are:
> >>
> >> Starphire Glass
> >>
> >> Transmisson: (@ 5.6mm thick)
> >>
> >> @330 nm < 5%
> >>
> >> @350 50%
> >>
> >> @380-680 nm 90%+
> >>
> >> I am wondering if somewhere in your research you did not confuse
> >> Starphire glass with Sapphire glass? In fact, the figures you cited
> >> in the 1999 message for Starphire are much closer to current
> >> transmission figures I was able to get today on the web for Sapphire
> >> glass.
> >>
> >> Sandy
Received on Thu Nov 17 00:07:56 2005