24-105 is my first L lens. It gives good pictures(not tack sharp pics) when shot outdoor, but when shot indoor and when light is of the essence it fails miserably.It does a slimy job when compared with the pics taken with primes or lenses with big apertures. I have the canon primes 24mm,100mm and 135mm and 50mm(sigma) and when I compare the pics taken with 24-105, this lens does not even come close with the pics I took with primes. If you have a good camera like 5D series, I would strongly recommend you to get primes or lenses with big apertures.