well right now I've just been using the sun but the new emulsion I bought doesn't allow you to use the sun. You defiantly need an exposure unit, so I'm just gonna build one
That would be the bulb, although I bought 'em cheaper at TopBulb. You can also get 24" ones if you don't need an exposure unit that large. The one I slapped together is 48" with 10 bulbs packed in there. Looks like a tanning bed.