Success! screw-in fluro BLB UV lightbox

From: [email protected]
Date: 06/23/05-09:49:44 AM Z
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I have declared my lightbox that has six of the screw-in fluorescent black light bulbs as the UV source a success, as I just pulled my first cyanotype test print last night. I undercooked the print a bit (or maybe not enough sensitizer, or ...), but I was able to determine from this first attempt that the box does evenly radiate over an 8.5 x 11 inch surface. As I do more tests and get the timing/distance and other variables down I will scan and post the results on my web site. There were a lot of firsts with this print. Here's a little more about this lightbox adventure...humor is intended :-) in the telling of this tale.

I gave myself a D in carpentry, but later upgraded the rating to a C since the box did come out level, it just looks a bit funny! I gave myself an R for resourcefulness in parts and materials used and have now added to my notes an A for functionality! Scale is 1(low) - 4 (high): A=4; B=3; C=2; D=1; F = no such rating as 0 (failure) because something is always learned :-) ; and R = outfield!

Funny it may be, but it was reasonably economical to make. The three expensive items were the 6 bulbs at $12 each; 2 lighting fixture strips with 3 ceramic sockets at $16 each; a 4 inch fan from Radio Shack cost $25; additional wood and hardware added to what I had on hand cost about $25 - $30. I described my design in an earlier email - two rows of the bulbs spaced 6 inches from center to center of each bulb with 3 inches to the sides of the box also (Inner dimensions of the box are 12 inches wide x 18 inches long - a perfect size for Photoformulary's beautifully made 8x10 contact printing frame.). I attached each end of the fixtures with a screw securely to a 0.5 x 2 x 12 that also serves as part of the box frame. Since the fixtures were designed to attach flat against a wall, the short wires were now sticking up from the top of my lightbox. I attached them to the corresponding wires of a small-appliance cord, which plugs into an appliance strip along with the fan cord
 ; a flip of the switch starts both lights and fan at the same time. I filled the space between the metal frames of the light fixtures, and on each side, with strips of board, then made a box top to cover (and protect) the wiring and make the top light-tight.

Enough said about the construction...except one more item...the nice thing about using the screw-in bulbs is that I was able to test the wiring with inexpensive, everyday, 40-watt, household light bulbs and not risk the expensive BLBs!

The test strip negative I am using is also a first - my first digineg; no, actually it is my second. As I attempted to faithfully follow Dan Burkholder's directions in the "Inkjet Negative Companion" I forgot to change one printer setting and my first digineg came off my Epson 2200 looking like someone's pinstriped suit! I corrected that little mistake and my second digineg looks pretty nice.

Next step of course was sensitizing the paper; two trials with coffee and a glass rod worked perfectly, nicely even color with no puddles. Then the first attempt with the new cyanotype solution (I did let it ripen for two days.) puddled and crystallized over most of the paper as I left it to air dry. Second try with less solution and a hair dryer did well. I am using some BFK Rives that I have on hand for these initial trials, but plan additional tests with Fabriano Artistico since most of you have indicated you like this paper for cyanotypes, though the BFK I have seems O.K.

Then came the exposure test! As stated initially, I didn't expose long enough (11 minutes at 4 inches from the UV source, though it may just be too little sensitizer) to get a nice dense dark-dark blue where my positive was black, but my test indicates to me that the light is falling evenly across the surface of the contact printing frame, which was what I wanted to determine with this first print anyway. For my test negative I made (in Photoshop) as strip of contiguous rectangles from 100% to 5 % (paper is 0%) at 5% increments and placed 4 of these (alternating end to end) side-by-side along with Dan's density "step-wedge" on the side. I have placed the positive as a jpeg on my web site so you can actually see what I am attempting to describe. That url is:

The printing frame did its job superbly, though I suspect folks in the next county heard the hardware snap when I secured the back in place...Smiles - a comment, not a complaint! The tiny little numbers (6 pt if I remember correctly) are nice and sharp! On the final print the cyanotype blues from my strips matched (visual check) the same percentages on Dan's strip - and they did also via electronic check of the negative in Photoshop. I don't have a densitometer.

Now to fine tune "my act" by manipulating some other variables (paper, amount of sensitizer, exposure time, negative density and color vs grayscale) and, not the least, more practice, more tests, more interesting images!

FYI: For drying the finished print I used a sheet of plastic needlepoint screen; these are inexpensive, readily available at fabric and craft stores, come in a variety of sizes and are stiff, sturdy, and smooth. My previous experience had shown that papers like Arches cover and BFK Rives dry flat on these plastic screens.

Thanks for reading to the end!

Judy Rowe Taylor
Mukilteo, WA
Art is a voice of the heart, a song of the soul. or
Received on Thu Jun 23 09:50:04 2005

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