You need to be aware of the parallax as well at close distances, there is a corrected AF frame option, but the actual point of focus will only display once you've, well, focussed, and so you may need to do it again if it's not where you want rather than recompose at close distance, especially if you're using f/2 etc. I found that I needed to use the corrected and the uncorrected frame to guesstimate where the camera was going to focus based on distance to desired point of focus. You can get it quite well after some practice, but it does not really allow a quick shot to be taken with any degree of accuracy.