ever since I got my 40mm "pancake" prime lens I can't stop using it, of the hundreds of puppy shots I've taken over these past 11 weeks the 40mm is the only lens I have been able to get great photos with, the autofocus is fast and smooth, and the F2.8 AP really helps in lowlight spots, over all I love this little wonder lens, and it's all I have been shooting lately too.