Should you ever focus manually? When?

Well, yes. Indeed there are circumstances where manual focus (setting lens or camera switch to manual focus, and turning the focus ring yourself) is the way to go.

And here’s a few of those circumstances. I can think of six right away:

1. Macro. When shooting macro, for instance when shooting flowers, bugs, food or jewelry, use live view and zoom in electronically if you can, then use manual focus.
2. You are using a Nikon D40/60/3000/5000 and a fast 50mm lens. Those lenses do not autofocus on those low-end Nikon cameras, so you have to do it by hand.
3. It is night. Your camera cannot focus well in the dark.
4. When shooting through glass, like on an airplane.
5. The subject has low contrast. Ditto – you may have to do it by hand.
6. When the subject is unpredictable in time but not in space – like fireworks. Or sports, when you know where the action will be. Pre-focus there manually!

Tip: Do not confuse manual focus with “using one focus point”. When using autofocus, you should always (or virtually always) use one focus point. When the camera chooses it will choose what you do not want to see sharp.

Homework: go take ten pictures right now where you focus manually. You;ll see how easy it is, and how consistent once you get it right.