What wattage is the halogen? Back when I had a home-made halogen unit, it was 1000 watts,and took in the neighborhood of 5 minutes per screen. One thing to watch out for with halogens is they're HOT! We burned too many screens in a row one day, and the glass got so hot that when it cooled down, it cracked in half.
I also used an old mercury vapor street light for a while, but the problem with them is they take 10 minutes to warm up to full brightness, so I had to devise a curtain between the glass & the lamp, so I could leave the lamp on for as long as we were shooting screens.
The best lamp I've used by far is the metal halide that Richmond puts in its Solarbeam units, but the halogen was pretty good for detail, too.
As far as distance from the screen, you want it far enough to spread evenly, so the size of the screens may dictate that. If you're just using manual T-shirt screens, like a 20 x 24 inch frame, that you can probably get by with having the light 2 feet from the screen, but you might want to experiment with this. If it's too close, you'll have an exposed area in the middle, and an underexposed ring around it towards the edges.
What wattage is the halogen? Back when I had a home-made halogen unit, it was 1000 watts,and took in the neighborhood of 5 minutes per screen. One thing to watch out for with halogens is they're HOT! We burned too many screens in a row one day, and the glass got so hot that when it cooled down, it cracked in half.
I also used an old mercury vapor street light for a while, but the problem with them is they take 10 minutes to warm up to full brightness, so I had to devise a curtain between the glass & the lamp, so I could leave the lamp on for as long as we were shooting screens.
The best lamp I've used by far is the metal halide that Richmond puts in its Solarbeam units, but the halogen was pretty good for detail, too.
As far as distance from the screen, you want it far enough to spread evenly, so the size of the screens may dictate that. If you're just using manual T-shirt screens, like a 20 x 24 inch frame, that you can probably get by with having the light 2 feet from the screen, but you might want to experiment with this. If it's too close, you'll have an exposed area in the middle, and an underexposed ring around it towards the edges.
It's a 500 watt bulb. It came with a beginner's kit I got from Ryonet a while back. They recommend having it 16" away from the glass, though I've heard that may be too close. I have the casing at 18", and the bulb is probably around 21" away. They say to expose it for 12 and a half minutes. But I feel like further away at a longer time may be better. Any ideas?
I had a unfiltered blacklite rig, but it's so worn out it takes literally over 120 minutes to burn an extremely shadowed screen.
! suppose 10-12 minutes should do it with a 500 watt bulb, depending on the mesh count. You're going to have to experiment a bit, but that's a good starting point. Fluorescent tubes are for the birds -- be glad you're getting out of the blacklight rig. too much undercutting to be able to do halftones.
It may be worth noting that the sun is a pretty good light source, too. i had my exposure unit go down a few years ago, and I got by for a day or two by spray-tacking the positives to the back of the screen and holding them in the sun for 2-3 minutes. Of course,this doesn't work too well on a cloudy day, but the sun is actually the best pin-light source there is. (There's always a work-around!)
With some experimenting, I've found 500 watts, 18" away will burn 0.5 lines and grid patterns in 12 and a half minutes. And for some reason, It looks exactly the same up to 15 minutes, so I don't have to run as fast into the basement.
I use the 500watts that comes with one of the packages from Ryonet, I keep it at 16" from the screen, I connected the light to a timer, set the timer at 12min. It has always worked just fine for me. I can go upstairs and the timer will turn off the light after 12min.
If you don't already own one, I will suggest you get a pressure washer.
I bought one at Home Depot, a 1330psi that someone returned, so it was an open box, for 65 bucks.
Help with exposure times 
