As an architect I have lots of drafting lamps available. I like the kind that have both a circular florescent ring and a 100 watt incandescant.

The Ott lights and similar brands just don't have enough output for my taste. The output of a florescent is roughly 3X that of a incandecent of the same wattage, for example an 18 watt Ott lamp has about the same overall lumens of a 54 watt incandecant bulb.

You can purchase compact florescent bulbs that will fit into a standard screw bulb fixture. Look for 'daylight' or 'natural' type bulbs to get a good color balance.