From: Judy Seigel (jseigel@panix.com)
Date: 06/29/00-10:41:23 AM Z
On Thu, 29 Jun 2000, John W. Richardson wrote:
> The tubes with the blue filter are designated BLB. In the U.S. they
> are much more expensive thatn the unfiltered BL tubes.
Of course you know there's nothing like a general statement in alt-photo
to attract contradictions, as flies (is that the insect?) to honey: I
think it was last year someone from California announced his local store
was selling the BLB cheaper (maybe a closeout, to make way for a new disco
style) & since then the price differential has lowered, AFAIK.
BUT, in any event the BLB is NEVER (again guess i should add in my
experience) better than the BL, I've tested it a bit because my neighbor
got the BLB by mistake (a costly mistake at that time). Was at least a
third slower, and depending on paper contrastier, with a steeper top step,
though depending on negative that could be a plus.
The point is that most every emulsion has some sensitivity at various
points along the spectrum, and those other wavelengths can contribute to a
rounder fuller print. Then changes in emulsion can also change sensitivity
-- in other words, cutting out wavelengths can be useful for spectral
tests or special effects, but for our purposes is a waste of electricity.
As for "harmful rays" -- I believe the BL bulbs have nought below 360 --
or if they do the glass filters it out. You shouldn't look directly at ANY
light bulb, but UV rays don't reach beyond 40 inches ("They" say), and
if you're working at close range you can get UV goggles for $4. (I suppose
Today-type people don't know what a broken record is unless in the 100
meter hurdle, but I/you/we say this at intervals.)
The BL bulbs must also have some visible spectrum light or we wouldn't (I
think) see their light when lit. You can print many "alt" emulsions by
other fluorescent bulbs (bright white, daylight, etc.) but often quite
slow & very high contrast. HOWEVER, that "Sunshine" bulb Erin mentions
sounds like --well, how could you not try it? Is it expensive? I used to
test 4x5 negs with just 2 bulbs.... and you could always put them in the
kitchen or give to your depressed cousin if they don't print (I assume
they're being marketed for SAD, or "seasonal affective disorder,"
depression in winter due to lack of UV rays on the inner eyeball.)
Judy
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