But whenever I tried those CFs they didn't show marring *nearly* as well as my high-wattage incandescents. Don't mean to sound :argue I just never got good swirl-spotting from them.
I know, I'm a broken record on this but a 300w incandescent in an otherwise dark room it simply unmatched in my experience and I've spent a crazy amount of time/effort on this.
It's made for high-wattage bulbs (and I think that's significant). There'll be a tag/sticker/something that says what wattage it's rated for. I got mine at Lowe's for about $20. Cheap, crappy-looking thing with a so-so spring clamp for a handle. Not even an on/off switch but it does the job.