Let's do simple camera move around the object. We want to also to watch the object all the time. There is many ways to do this and here is couple of them.
Linear Track to Constraint
There is couple ways to make camera to track object while moving. Probably the easiest way is just drop "Track To Constraint" to the camera and set object to target. And then just add keyframes…
Set “Track To Constraint” easily in Blender with just selecting camera and then object that you want to track. And then just press CTRL + T
But what happend when you wan’t to make smooth camera moves between two points that have different vertical value and same time use "Track to Object".
With simple poin to point animation and "Track To Constraint" you got “bumpy” camera move like this. You can do circular path with make more keyframes, but that isn’t so clever.
There could be situations where you want this bumpy feeling, but today I need to make more smooth rotation around the object. Like this. I want to make that camera path more circular than just straight.
So I just tested out couple ways to do it. And yes, there is many more way to do this…
Usually I used the "Follow Path Modifier" and “Track To Modifier” combination and it works fine. But with that I need to make curve object. This isn’t problem usually and I got very much of control, because I just can edit curve points and effect the path in that way.
Another Solution (Limit Distance Modifier)
There is easy way to make this kind simple camera animation to be more smoother and similar as we have with a curves.
Just add "Limit Distance Modifier" and set distance to nearest value when your object is from the camera. Use it with "Track To Constraint" to keep camera pointed to the object.
Measure is easy with this constraint. Just go frame where your camera is nearest point from that object and press "Reset Distance". It will automatically update the value and your you’re ready to go!
Simple as that. But at the end I think curves is still better ways to do this kind camera animation because you have much more control then…