Re: Lightsource for Gum Bichromates
Hi Bjørn,
The UV tubes print much faster! Gum under 125 W HPR' needs 6 to 10
minute exposure compared to 2-5 minutes under a UV 20W unit. There are
some more differences because the TL is diffuse lightsource compared
to the more point source nature of the mercury vapor lamps. you have
to adjust your curves when usig diginegs.
kees
On 25 jul 2008, at 09:56, Bjørn Frostad wrote:
Thanks Loris!
I've noticed these 40W's myself - but won't the exposure time be
awfully long compared to a 125W bulb...?
Bjørn
----- Original Message ----- From: "Loris Medici" <mail@loris.medici.name
>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, July 25, 2008 7:55 AM
Subject: Re: Lightsource for Gum Bichromates
My bulbs also are Philips brand. I use 24" (60cm) 40W UBVL tubes.
The bulb
number was TLK40W/05 or something like that (/05 is the suffix for
actinic
light).
Regards,
Loris.
24 Temmuz 2008, PerÅŸembe, 6:17 pm tarihinde, Christina Z. Anderson
yazmış:
Bjorn,
I use Phillips UVBL tubes for all my gum prints. If I was at home
I could
look at the bulb number, but they are blue lights, not the deep
Jimmy
Hendrix purple but pale blue/lavender.
Chris
----- Original Message -----
From: Bjørn Frostad
To: alt-photo-process-l@usask.ca
Sent: Wednesday, July 23, 2008 4:23 PM
Subject: Lightsource for Gum Bichromates
Since the Phillips HPR 125 apparently has been discontinued, I'll
have to
go
for the next best alternative for making my gum-prints.
But - ....I can't seem to find it........
Any ideas?
Bjørn Frostad, Norway
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