DIY Exposure Unit: Unfiltered Blacklight Tubes vs 1000 Watt Metal Halide Grow Light??
I need your opinion and the title of this post says it all: unfiltered blacklight tubes or a single 1000 watt metal halide grow light? I was all about unfiltered blacklights, but I'm moving into more detailed prints with quite a bit of halftone complexity.
While I never had any troubles getting the detail I needed with a blacklight box, I recently read this article: http://www.murakamiscreen.com/docume...Comparison.pdf and now all bets are off. All that junk about cross linking, and histograms...well, I get it, but I don't know how much it will really effect me.
An old post I read had AndyMac on record as saying 1000-watt metal halide grow light is his backup (for the sun? That's O.G.) Anyway, I don't know if this still holds true.
If it's of any concern, I have really good positives, both inkjet films off an Epson 4880 and plotter-cut Rubylith. I've been exposing at school and we have a professionally-built metal halide unit with a light integrator. It's really nice (burns in 13 seconds), but I graduate in 6 weeks, so I'm looking to use those last 6 weeks in the woodshop to build something that will work post-graduation. Also, I've been using Ulano TZ, but as of today grabbed a quart of Ulano Proclaim and Proclaim-HR – mostly because our darkroom is less than 'dark' and the washout station is under fluorescent lights and anything too fast-burning gets over exposed in the washout process. When I move to my own setup I'm hoping to remove that from the equation.
I still use a grow lamp, but lots of people get good results from the bulbs.
Depending on distance back from the glass required for larger frames, the 1k lamp will take a while to expose - 17 minutes for me with a cold bulb, 12 if warmed up. fluorescent UV tubes are instant on and exposures are usually shorter depending on emulsion.
Thanks for weighing in guys. I'm burning 21" x 31" screens, so that might be a while. I guess my priority would be detail –*I can always find something to do for 12-17 minutes. But there's something to be said for a quick burn sometimes.
And I'm going to miss that exposure unit. 13 seconds is pretty awesome. I can burn 4 screens with washout in about 5-6 minutes. That's going to be hard to give up...
I recently switched from tubes to a metal halide grow light, I use 305 screens primarily and draw fine lines with a .25 rapidograph, and occasionally halftones. The tubes had a tendency to shrink the the thickness of my lines, though not too much. I've noticed a greater sharpness to my halftones as well.