I have used a standard enlarger bulb in a condenser enlargers, first 1965 in high school, we used poly- contrast, printed all grades, then in college and in the Air Force added GAF, Dupont, and Ilfrod, never had a issue printing grade 1 to 5 with correct filters. Currently I print with color head, condenser, and very old Federal diffuser with enlarger bulbs, the Federal uses a clear bulb, I use LED bulbs in my D3. With LED bulb, highest grade I get to with 1200 lum is grade 3 or 3 1/2 which works for most negatives, with Omega cold lit, need to add 40CC yellow and can print grade 3 to 4. Maybe I've doing it all wrong, just didn't know any better.