Here are some pics from my newest light source,  I used those CFI black lights.  I already use a black lights tubes as a light source.  I was intriqued by the CFI black lights so I built the following light box.  I can only use an 8 x 10 contact print frame.  I started by using only one light blub, then 4 and then 9.  What is interesting is that there is more heat using these bulbs and my other unit runs cooler even though it has a smaller fan.  For exposure time it's a little longer than tubes.  The bulbs screw into ceramic sockets.