Depth of field

Assignment #2 is to experiment with depth of field, which is something I love (or should I say...I've discovered that I love taking photos with a shallow depth of field). Here's the first photo with an aperture of F/5.7:

And an aperture of F/16:

I couldn't quite get both figures fully in focus...the picture seemed to go a little soft. I don't know if that's the lens or me (probably me). The next assignment is shutter speed!