Re: BL vs BLB tubes for cyanotype

Hi Mark,

Yes, a spectrophotometer would be the thing we need. If we all had a
spectrophotometer we could take all of the speculation and guesswork
about the transmission properties of glass out of the equation.

You see them on ebay from time to time, but they usually go for more
than I am prepared to spend for something that I probably would not
use but once or twice a year. But you might find one very useful for
your tests with digital negatives from various printers on different
substrates in conjunction with PDN.

Sandy

>Sandy,
>
>What instrument would one use to measure the spectrum of light
>passing through some material such as the glass you are talking
>about? Where might one get access to one? Would my doctor's
>colonoscope work?
>
>Would it be a Spectrophotometer?
>
>
>Thanks,
>Best Wishes,
>Mark Nelson
><http://www.precisiondigitalnegatives.com/>Precision Digital Negatives
>PDNPrint Forum @ Yahoo Groups
><http://www.markinelsonphoto.com/>www.MarkINelsonPhoto.com
>
>In a message dated 11/16/05 9:18:48 PM, sanking@clemson.edu writes:
>
>>Well, not quite 909%. The intended percentage was 90%.
>>
>>Sandy
>>
>
>
>
>
>
>
>Best Wishes,
>Mark Nelson
><http://www.precisiondigitalnegatives.com/>Precision Digital Negatives
>PDNPrint Forum @ Yahoo Groups
><http://www.markinelsonphoto.com/>www.MarkINelsonPhoto.com
Received on Thu Nov 17 08:21:40 2005