reply to Sandy Re: UV exposure light boxes

Aye, i got a really good setup worked out.

My real issue is with the density of my enlarged negative image from
120. I am printing albumen and am indecisive about what really dense
actually means... So I tried one out at really dense, and it didn't
print with an all night exposure.. :)

i'm printing 20x24 so i have a lot of tasks to over come right now, but
it'll be good. i'll show a link to a website with the contents if u
guys wanna see it in 3 months when i'm done.

On Feb 3, 2004, at 11:58 AM, Sandy King wrote:

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>> Aight, so I just made a exposure unit. Using GE UVBL bulbs. I have
>> 3 dual fixtures in this box and I'm getting a weak exposure. It
>> could be other factors, but I'm leaning towards thinking that the
>> fixtures aren't delivering enough power to each of the bulbs.
>>
>> Does anyone know circuitry theory? I have 3 20Watt ballasts coming
>> out of the single source of current. How many could I have without
>> running risks of low voltage?
>>
>> Thanks to the techies.
>> adam.
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> Most 120 volt AC outlets can handle at least 1200 watts (think hair
> dryers!!, ceramic space heaters, etc.) and you are not even close to
> that figure. I am strongly inclined to believe that the reason for the
> apparently weak exposures is due to some other cause.
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> Some folks are always on the look-out for lights and systems that are
> more efficient that UV banks of fluorescent tubes. However, the fact
> of the matter is that a well-constructed bank of UV tubes, and the BL
> tube probably the best all-around one, puts out prodigious amounts of
> UV radiation. Some 1000 watt metal halide systems may give shorter
> exposures with small prints (say 5X7 or 8X10) since you can use
> place them at 8-10". However, for anything over about 11X14" the UV
> bank of tubes is hard to beat when you weigh economy of use, ease of
> operation, printing speed, and even illumination.
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> In my own work I use both a large bank of BLB tubes (which print
> slightly slower than BLs) and a NuArc 26-1K plateburner. The bank of
> BLB tubes prints about 25-35% faster than the NuArc.
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> Sandy
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Received on Tue Feb 3 19:45:09 2004