One thing .. be careful with your terminology.
...Put the red figurine up on a pedestal(she seems to be the star of the moment anyhow!
) .. and use her as the focus point.
Put Snoopy on the sidelines still in the frame, as a gauge on focus depth.
The red figurine has more contrasting patterns and lines for focus not get confused, whereas snoopy can cause focus locking errors.
Keep it low
light. F/2 and f/4 or f/5.6 should be sufficient for determining if you do have a focusing issue with this
lens on this camera or not.
Something else that you can do as well. You don't need to actually take the shot .. this is more for confirmation purposes and posting questions to others.
As you have liveview, what you can do is to focus, using Ai mode, briefly .. say a second or so,
stop and then switch to Lv mode.
Zoom in to 100% view and determine if the image looks
sharp on the review screen. If it's
sharp, great. If it looks slightly blurry, you can 'jimmy' the
lens' focus collar to get a sharper looking image.
The trick is to determine which way you need to adjust focus on the
lens, and by (roughly) how much.
two or three runs should be enough .. but be sure to defocus the
lens before each run .. and do so both ways(that is, throw focus out towards infinity and then the next attempt towards minimum focus distance too).
Repeat the above test in Single shot AF mode too .. just to see what happens, and if it works differently to Ai mode.