Recently, I purchased an Omega Chromega XL 4x5 enlarger outfit for a very reasonable price. (I couldn't resist!) I got all the stuff, including lensboards, turet, a Condit pin registration punch (free), etc.

As to my question, I've always thought of enlarging with incondenscent lighting as being consistent, at least more consistent than cold light. But, how consistent would this light source be for variable contrast printing? For example, color temperature probably also changes over time. Does the intensity vary significantly over time? How often should one need to change bulbs to get the most consistent lighting?

I have a compensating timer with an extra sensor, so this would help to stabilize intensity.