U of S | Mailing List Archive | alt-photo-process-l | Re: Yellow tents and UV (was: outdoor gum demo)

Re: Yellow tents and UV (was: outdoor gum demo)

A little below says:

  	The printing speed of this paper requires exposures be made by contact
under illumination by a strong ultraviolet light source, such as direct
sunlight, open sky, mercury vapor lamp, or black light printer.
Exposure times with such sources will be measured in minutes. Increased
contrast, of more than one printing grade, may be achieved by exposing
for extremely long durations (24 hours or more) under fluorescent

So any blue sensitivity is probably not enough to form an image, maybe it
was mentioned because it can slightly fog the paper - who knows? "24h
fluorescent light exposure?" -> Even ordinary enlarging paper will
considerably change tone at that level of exposure to visible light.


22 Nisan 2009, Çarşamba, 11:02 pm tarihinde, Paul Viapiano yazmış:
> Centennial POP (Chicago Albumen Works) was (sniff!) sensitive to blue and
> UV
> only...(from their website).
> http://www.albumenworks.com/directions.html
> Paul
> ----- Original Message -----
> From: "Katharine Thayer" <kthayer@pacifier.com>
> To: <alt-photo-process-l@usask.ca>
> Sent: Wednesday, April 22, 2009 11:57 AM
> Subject: Re: Yellow tents and UV (was: outdoor gum demo)
>> On Apr 22, 2009, at 11:29 AM, Paul Viapiano wrote:
>>> Now, of course, if there is cloud cover then all bets are off...
>>> I say this partly in jest because in my Darkroom 1 book (Lustrum
>>> Press),
>>> Linda Connor (whose exhibit I've just seen at the CCP in  Tucson) said
>>> that sometimes she'd leave a POP print out on her back  porch for 3 or
>>> 4
>>> days!
>> But that's a gelatin-silver chloride process exposed with visible
>> light,
>> no?  Apples and oranges, sorry.   Of course if there's not  much visible
>> light, it's going to take some time to make a print that  depends on
>> visible light.  But the amount of visible light isn't a  measure of UVA.
>> I've exposed gum prints in the shade in 3 minutes,  and no, they weren't
>> underexposed.
>> kt