U of S | Mailing List Archive | alt-photo-process-l | RE: light source for contact printing

RE: light source for contact printing



"...The center to center distance with my exposure unit is 20mm..."

Sorry for the typo, I actually meant:
"...The center to center distance with my exposure unit is 60mm..." (In
other words, tubes are 20mm apart)

Regards,
Loris.

-----Original Message-----
From: Loris Medici [mailto:mail@loris.medici.name] 
Sent: Wednesday, February 07, 2007 8:26 AM
To: alt-photo-process-l@usask.ca
Subject: RE: light source for contact printing


Erich & Alfonso,

FWIW, 05 TL / TLK tubes' useful life is circa 2000 hours (actually 3000
hours, but their output is reduced in the last 1000 hours), so maybe
it's better to opt for them. Also, ballasts are very important as you
note -> it's better to use electronic ballasts for best performance +
longer life...

The center to center distance with my exposure unit is 20mm (I can put
my fingers between the tubes, therefore can fiddle with a tube that is
in the middle in case of a problem ) and tube to glass distance is 45mm
-> I get no light banding with this setup + I can cover up to 40x60cm
with just 8 tubes.

Regards,
Loris.

-----Original Message-----
From: Erich Camerling [mailto:e.camerling@tiscali.nl] 
Sent: Wednesday, February 07, 2007 8:07 AM
To: alfondc@gmail.com
Subject: light source for contact printing


Dear Alfonso,

The best light source ,in my opinion, for contact printing  is a
self-made one.I made a wooden packing-case (size ~ 65 x 55 x 22 cm)
Inside I mounted 10 TL tubes : 40 Watt Philips Cleo Performance (length
59 cm. EOC (European Order Code) : 62830540 or 62835040 (with
reflector).Ordering number 9280 031 20900 or 9280 045 20900
(R).Radiation 313 - 400 nm.Peak 350 nm.Application : cosmetic tanning
and photochemical processes. useful life : 500 hours ) About 30 %
cheaper than 03 TL tubes from Philips (380 - 480 nm). About the same
price as 05 TL tubes (300 - 460 nm). The distance centre to centre : 50
mm. Distance to the film ~65 mm. Heat discharge by 6 small (computer)
ventilators from unassorted goods. Most expensive are the ballasts for
the tubes,so I used second hand ones.(but don't buy old ones which
worked on 220 V,you need 230 V). Hope this information will help you.

                                      Kind regards

                                        Erich