Live time and live bulb: Is it really a free lunch?

In my limited field testing, long exposures shot with live bulb are somewhat more noisy than comparable ones (in terms of exposure) shot without live bulb.

So I guess you're kinda right, using live bulb does introduce some extra noise, and the longer the exposure / number of readouts the more noise creeps into the image.At least this is what I've found in my limited field testing.