I used condenser enlargers for years because here in Texas things used to move slowly. I learned to print on a condenser enlarger and learned to be a pretty good printer. For some reason and I don't remember why, I bought a coldlight and put it on my D2v Omega and I think I became a better printer right then. I currently have a closed loop system with that Metrolux II timer and the Aristo VCL 4500 head for the D2v. It has a blue and a green tube. It is everything I want in an enlarger light source and timer. So, to sum it up...Magic.