Uva alt print box

[Gary Beasley]

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.

[Tin Can]

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

[Jim Noel]

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

[Pete Roody]

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

I do plan to install a light blocking door on my unit, ASAP

Soon I will test Sun VS my iteration with a UV meter, that peaks in UVA before engaging in any printing

When young in the 50's and 60's I did ski without sunglasses

I found I preferred night skiing, perhaps too late

Time is of the essence for everyone now

[Tin Can]

Jim, I am new to alt printing, never done any of it

I will start with VDB with existing Rodinal negs

I will take my time, as time is all we have now

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

[Tin Can]

Thank you

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

[Vaughn]

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.

[Tin Can]

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!

[Jim Noel]

Jim, I am new to alt printing, never done any of it

I will start with VDB with existing Rodinal negs

I will take my time, as time is all we have now

And I probably have less of it remaining than most. BUT, i just keep on pedaling.

[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

And I probably have less of it remaining than most. BUT, i just keep on pedaling.