Keep in mind that fast lenses can be valuable even if you never shoot wide open. This is because of the brighter viewfinder you get with fast lenses. On several occasions when shooting in poor light (before sunrise) I've switched from my 20/2.8 to the 24/2.0 because I simply couldn't see how I was framing the scene with the f/2.8 lens.
-- Mark Roberts Photography and writing www.robertstech.com
