Thank you for all the comments about the hammer missing the nail. Actually I started the exposure with the hammer ON the nail, then slowly raised it. After looking closely at the photo I realized that the nail raised slightly after I lifted the hammer. I took the photo in my living room, on top of my cushioned piano bench. I didn't think about the cushion compressing under the weight of the hammer! But that's what this site is all about...learning from your mistakes!
Nice technique, but I think you mised the nail! I tried a similar technique with anther challenge and it is really hard to keep focus. You did a pretty good job of it.
Why is the head of the nail showing here? Shouldn't it be under the head of the hammer?
I think that gives away the illusion you were trying to create of the hammer stirking the nail in your set-up shot.