hello, i just bought my first L series lens, the 100-400mm but i am a bit disapointed about the IS sistem which is garbage.i also have the 70-300mm IS and the IS works amazing,i know is not the same IS but still......i mean i can see it working (i can hear it also -it is clicking and humming for a while)but the amount of correction is neglijible.is my lens broken or this is how it works?





thank you