How do you level your turntable?

I picking up a pair of cables at a fellow A'goner's house a couple of weeks ago and he showed me an interesting experiment relating to bubble levels. He showed me 4 bubble levels on the same surface, each of which had a different reading. He explained that these are all hand calibrated using some sort of photographic device, which explains for the discrepancies between the bubble levels. He said he uses a digital level for his turntable, which is the best way to achieve a perfectly leveled table. FWIW, he's an architect and an engineering professor at a major university.

Me, I use a bubble level because I'm feeling cheap.

Dougdeacon has the answer to this. I have $500- worth of levels to install fine cabinetry and I always rotate 180 degrees and halve to find dead nuts. The ONLY way to find true level with a bubble.

Ditto Doug/Zen

A 9" "torpedo" bubble level works great. $4-5 dollars at Lowes or Home depo. A torpedo level gives you a north-south, east-west and diagonal level reading at the same time.

Actually, a 9' torpedo oughta level things very well. ;-)