> I hadn't *noticed* it either, but in a fit of anxiety one day (really so
> much testing must, ultimately, be from anxiety) I put five of my set of
> nine identical 4x5 negatives (that was before the reign of the 21-step) in
> the 4 corners and center of the print stage, covering an area slightly
> larger than an 11x14 inch print -- at a height of THIRTY inches! The
> corner prints were *dramatically* lighter than the center print. I did not
> use the bulb again.
OK, that makes some sense to me. I was a bit concerned trying 8x10 at 24
inches. If there was a problem I didn't notice it.
> Other drawbacks of sunlamp: a lot of electricity. You can light 6
> blacklight fluorescents for only 120 watts, less than half, without heat.
> Fluorescents also last something like 9000 hours: My fleamarket sunlamp
> bulb was rated for only 25 hours. Then you were supposed to wait 5
> minutes before turning it on again -- and you could *really* get a
> sunburn. Etc.
I know, I know ... I'm looking to replace it. Thought I'd build a new
source later this summer. In the meantime, I'll probably just us plain
old sunlight.
> We ran a thread a couple of years ago when (as I recall) Sam Wang and
> Sandy King tested the difference in contrast from different light sources
> for carbon. They tested daylight fluorescents (which Phil Davis used) vs.
> blacklight fluorescents, that had been the norm til then. They found
> (this from memory) they got a contrast they liked better with the daylight
> bulbs, bought for $3 each at -- whatever nice source you have in the
> HEARTLAND that we lack here in tourist-ville, where my local hardware
> store, wedged between a sidewalk cafe and a custom leather shop, charges
> $7 apiece for fluorescents...
I saved the messages from this thread when it happened. Will try to go
back and read them again before upgrading my light source.
> We used to have an expression I never got the meaning of, "call me
> anything but late for breakfast." (Maybe some other phrase collector can
> explain?) So.... anything but *newsletter*....;- ) For 15 years I edited
> the world's most obscure artists' publication which, nevertheless, WE
> thought of as a magazine, or quarterly. We never did get people to stop
> calling it newsletter. But rest assured, we never held it against them
> (much).
OK, sorry my mistake.
- Wayde
(wallen@boulder.nist.gov)