If the times are too short you can also raise the tubes above the glass, double the distance should be 4x the time and so on. If you had yours as high as mine I would expect a 3-5 minute time with van dykes.
If the times are too short you can also raise the tubes above the glass, double the distance should be 4x the time and so on. If you had yours as high as mine I would expect a 3-5 minute time with van dykes.
Short test today
Used a meter that gave
My box 1300 units
Direct Sun 1700 units
Units are just numbers to allow comparison
60 seconds each, no glass, meter claims UV 350 to 490 nm and it doesn't read anything inside my home with any light I am using
Then the sheriff drove by, we both waved, but he did do a double take on my device, which looks like a calculator
Before you ask, mine is out of production, there are many here https://www.amazon.com/s?k=uv+light+...sl_eyn27nghn_e
Tin Can
I am interested in your actual print times for Pd, VDB and/or ziatype.
If I don't use a ND filter my times for Ziatype run 60-120 seconds, Pd just over double that. MY contact frame is 1.5" from the fluorescent tubes. I rarely use my mercury vapor unit any more.
90% of negatives are developed in PCAt HD.
Thanks,
Jim
It's always a good idea to wear eye protection when working with UV printers even if you block most of the light.
From Talas:
https://www.talasonline.com/UV-Absorbing-Spectacles
Hey, TC -- could you run a quick test for me with your lights and UV meter? The idea would be to test the amount UV received at different distances from your lamps. I have a feeling it will not follow the 'square of the distance' rule, but would like a field check. Just two, or at most three different heights.
I do not have my lights set up right now, but will do the same with them (750W self-ballasted Merc vapor bulbs) one of these days.
Vaughn
Edited to add: Don't worry about it if your set-up does not allow for that to be tested easily...just curiousity.
"Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China
Vaughn
Data just now
Removed the highly reflective NuArc Vac frame
Then used bare plywood at 7" bottom of my box
Next a 11X14" traditional and thick split back contact frame with a black dark-slide at 5" to eliminate reflections
Then added a another black block to get to 2" below tubes
Again 1 minute at center of lamps
7" = 1205
5" = 1257
2" = 1286
I may try aluminum foil at bottom and later matte black paint after using it for VDB for a while
Any suggestions are welcome!
Tin Can
Love your analogy, I really like pedaling!
My peers, back in the 70's, called ourselves, 'Sleep when you are dead group'
even got the Cubs at Wrigley field to show that phrase on the scoreboard, 'Welcome the Sleep When We are Dead Group'
some of us were sleeping in the hot Sun...
2 have passed
So it goes
Tin Can
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