I'm fairly new to the world of large format photography, so I'm not sure how to diagnose my problems here. I've just started scanning the film I've been exposing and developing over the past couple months and I've noticed that some images look very sharp and clear, while others seem somehow dreamy. I'm not sure if this is a focus question, an exposure question, or what, but I'm hoping that if I post a couple images here for comparison's sake some one might have a guess at what I'm doing right/wrong.

(I have to post fairly small files because my internet connection is terribly slow, but the difference in the two photos should be clear)