Re: light table (fwd)
wmlaven@well.com
Sun, 1 Dec 1996 17:03:44 -0800 (PST)
>On Sun, 1 Dec 1996 wmlaven@well.com wrote:
>> box made so that your contact frame will flip over, face down, and sit on
>> top of the box, sealing it and eliminating any UV from leaking out (good,
>> beccause you may not "see" it, but UV is in the dakroom and its bad for
>> your eyes). The nice things about this type of unit is for those with small
>
>Of course it's always better to err on the side of safety, but as I
>understand the operation of Black Light fluorescent bulbs, they may emit a
>certain amount of light below the visible spectrum, but still, we see
>light when the bulbs are on. In other words, if light escapes from your
>light table, it might include wavelengths not visible to us, but we would
>still see light, hence know UV was nigh.
>
>Judy
Yes, you're right that you can see when the bulbs are on, but in many of
the UV units I've seen (in my and others' darkrooms) there's only a small
crack where the light leaks and many people close the printer, then
proceeed to work near it and the leak is so barely noticeable given the
brightness of the room (via the general lighting) that they forget they're
still being exposed to UV rays. As a test, I once closed my dakroom doors,
turned off the room lights and turned on the UV light unit which I thought
I had sealed well around the cracks and edges. Although I couldn't see UV
light emitted with the room lights on, I was amazed at how much holy blue
glow was actually bouncing around the room. I then resealed the unit until
it really was sealed as confirmed with my lights-off test.
Bill