It’s a basic in photography, mastering the depth of field, the part of your photo that will be in focus. It took me years to be able to remember how to do this.
It finally clicked; the lower the Fstop (aperture) number the narrower the depth of field, which creates that wonderful blurry background we all love so much.
In this particular shot I found out that an aperture set at 4 (the lowest this lens will go) was just a little too narrow, I couldn’t get enough of the apple in front in focus for my taste. Going up to 4.5 did the trick for me.