Re: Questions about platemakers...

Judy Seigel (jseigel@panix.com)
Sat, 3 Jun 1995 01:32:33 -0400 (EDT)

Hi Adam,

Whatthehell kind of fluorescent lights are you using to make your times
so long? I have both a NuArc Mercury Vapor vacuum whatever you call it,
cost now about $1700 plus shipping, and a bank of 7 blacklight
fluorescents butted up
against each other with the paper stage about 1 1/2 inches from the bulb
surface. Times are EXACTLY the same. (Well, as near as I can measure. 100
units on the NuArc takes about one minute and gives about the same
exposure as one minute on the fluorescents.)

In fact I had to INCREASE the distance from bulb to paper to get my times
long enough with the fluorescents for a little control! (Note, though,
that you want your bulb to extend a couple of inches past your negative
area on all sides for good edge-to-edge exposure.)

My guess is that your bulbs are too far apart and/ or too far away. I have
tried by the way to get "hot spots" or uneven exposure with the
fluorescents by putting the paper even CLOSER and so far haven't succeeded.

Anyway, what brand bulb are you using? My neighbor got some "no-brand"
bulbs on Canal Street, that were about 20 to 30% slower than my GE's.
(I've also used Sylvania, Phillips & Westinghouse, all fine.But batches
differ -- different grades & types of phosphor -- so get all your bulbs
same time same brand.)

Have you got the BL (just black light) or did you get the BLB, which is 3
times the price, but less light at the wave length you want. (BLB has got a
very expensive glass tube to cut out all wavelengths except the spooky
blue for discos. BLB stands for "Black Light Blue.") If you want to pay top
dollar for very reliable bulbs,
you can get the bulb Palladio sells (forget the name, starts with "V,").
The designation on that bulb is AQA -- made for aquariums, at 415
nanometers evidently exactly the sensitivity of platinum, though does the
others just fine -- also available in cartons of 20
(cheaper) from Bulbtronics on Long Island. But, again, these are NOT
necessary.

What width and length flourescent are you using? 24inch (20 watt) is a
handy size. The number after the T is the diameter -- T12 is fatter than
the T8 and for all I know gives more light -- anyway, that's what I've
always used. So eight 24-inch bulbs (cost about $12 each) costs $96. The
most
economical fixtures are gangs of 4, if you can find them, maybe $30 each.
$60 and $96 equals $156. And that's it! These bulbs, please note, are
rated for 2000 hours. Also, compare electricity usage -- in terms of
economy and conservation. Eight 24-watt fluorescents total 200 watts. I
don't know what most platemakers use, but it's lots more (mine has its
own 20 amp fuse). As for sunlamps -- FIE! FIE!! (The smallest I've seen
is 500 watts, and the light is criminally uneven.) Also, please note,
that it is ABSOLUTELY UNNECESSARY to wire in your own ballasts, etc. Go
to Home Depot, or whatever they have in your town, and get regular
fixtures. You do have to add the connecting wire, but at least you have
the basics built in.

Assuming my NuArc is typical (and don't get me wrong, I love it, or
love-hate it), the bulbs are rated for one year in "normal" shop use.
That's on-off throughout 5 days, maybe 6-8 hours a day. BUT, and this is
a BIG BUT -- the processes plateburners expose generally average 35 units.
Cyanotype averages 400 units, my neighbor's bulletproof negatives went up
to 900 units. Platinum & VDB between three and four-hundred units.

In other words, one fine day the bulb burns out and the replacement is
$90 plus shipping, plus at least a week delivery. That fine day led me
to haul the old fluorescents up from the cellar (I was in the middle of a
print at the time) & re-think the proposition.(It turned out, by the way,
when I installed the new $90 bulb that it wasn't the bulb after all, but
the fuse, and then it still didn't go on because I didn't rescrew in the
fuse cover quite all the way, which fine point cost me a $75 service call
to learn.)

Now I have the fluorescents plugged into one of those power strips and
the power strip goes into a gralab timer, so I have pretty good time
control. For precise testing I do use the NuArc, with its integrator, and
there is the vacuum frame part which is excellent -- but the thing is
HUGE, a terrible space eater. And weighs 10 tons. The flourescent set-up
knocks down in no time and weighs very
little. You can also, by the way, get an INTEGRATOR with a little sensor
to strap onto the fluorescent. About $300. And you can also, as I did for
years, switch the bulbs in your flourescent fixture if they're bottom
mounted for regular cool white flourescents, drop in a white plexi cover
instead of the clear glass and have a large-size light table.

I'm sorry this is pretty disorganized, but I wanted to reply
before you rushed out & bought a platemaker. Think again! I'll add that
I've been watching the posts about exposure lights & would say this is a
subject in which misinformation rules. (When/if I finish my
book-in-progress, "Negative Thinking," Number two in projected series is
"Non-Silver studio", with BIG chapter on exposure lights, all very
organized. )

Finally, if I were going to build a fluorescent table now doing my own
wiring (which is a lie, because I would NEVER do any electrical wiring
more complex than dialing my rotary phone), I'd look into the new digital
ballast. I understand that GE-MOTOROLA have got one. They promised to
send me price info & didn't, but here are two big advantages:
Installation is with a thumb plug, just like your modem. Also, no heat.
Which brings us to another topic, to save for another day --Do your
fluorescents heat up? Ho ho, mine don't -- because exposures are so SHORT!
If they do heat up, for consistent control, factor that in, that is, use
a fan, or let the whole deal heat (about 15 min.) before starting to print.

OK?

Cheers, Judy (from the land of Con Edison, world's most expensive &
obnoxious source of electricity, NYC)