CLF's are notorious for their annoying "warm-up" characteristic. In some instances, it takes a minute or more for a CLF to reach full light output.
Originally Posted by Donald Qualls
Most folks who use spiral BLBs for printing simply preheat the bulbs for a minute before starting the exposure. Since exposures in alternative processes are typicaly minutes, a little non-linearity is not normally a problem.
FWIW, I've studied the application of CFLs in our home pretty carefully. The basic economic analysis leads me to conclude that applications that are "on" for more than about 45 minutes per day will recover the higher cost of the CFL with the energy savings within the first year, so I've replaced every incandescent bulb that gets lots of usage. My next round of replacements will be where its a PITA to replace the bulb - have to get out a ladder, remove a cover, etc. I will not replace the bulbs where there is a need for the lamp to provide full output immediately (ie, the bathroom - when you stumble in there in the middle of the night, you need light NOW!), nor will I replace bulbs outdoors - CFLs don't start well when the ambient temperature is very cold.