Depends on your hold. I hold the body left hand flat on the palm, thumb rests on the lens and index finger on the release. Right hand under the lens for focus if WLF over if prism in that case hands stay in place and press finder to face to steady shot. With WLF I tend to support the lens and hood with right hand for the shot after focus pulling the camera into the body for stability. So the bubble just fits over my left hand but the leading edge can be a bit uncomfortable digging into the thumb sometimes so needs slight hold change. Obviously the bubble is useless with the prism finders, tripods excepted, but if you want level with WLF fantastic, it is very sensitive though and you can get paranoid centring it, like one of the those puzzle games. I use it less now as digital allows tilts after scanning but in the day for E6 work it was excellent.