From BlenderWiki

Animating Cameras

We won’t talk much here about standard “object” animation – as with lamps, you can use Ipos to control a camera location and rotation, but also constraints, like the ever-useful TrackTo one.

By the way, about tracking with a camera: unlike e.g. with lamps, when you track your main subject with your camera, you seldom want to center it in the view! To avoid this, I often use as camera target an empty, that I parent to my main point of interest. This way, by animating the position of the empty, you can easily control where in the view is your object, and still have the camera following it when it moves, without any additional effort.

But back to our subject. “Camera” animation regroups mainly its “lens” properties, so you can use it to control its focal, the depth of fields (whith renderers that know how to use it – Blender’s one doesn’t, but you have the Defocus compositing node for this effect), etc.

Options

The Camera set of Ipo curves is quite limited, and correspond to some of the settings of the Camera panel (Editing context, F9):

Lens

As you might have guessed, this controls the lens of your camera (in millimeters, I think… value ranges in [1.0, 250.0]). Useful for zooming (see the example below…).

Note that:

• The curve is always in “length” value, even when the D (i.e. “angle” mode) is enabled in the Camera panel.
• When your camera is orthographic, it controls its scale.

ClSta, ClEnd

These curves control the start and end points of the clipping distance (in Blender Units, values range in [0.0, 100.0] for ClSta, and [1.0, 5000.0] for ClEnd). It might be useful if you want to spare your computing power, by adjusting the clipping region narrowly to the needed objects, when rendering an animation…

Apert

I think this stands for “aperture”… But it seems to control nothing!

FDist

This controls the focus distance of the camera (its Dof Dist field), used e.g. by the Defocus compositing node (value ranges in [0.0, 5000.0]).

ShiftX, ShiftY

These curves control the shifting of the “image” plane inside the camera, respectively along the X and Y axes (values range in [-2.0, 2.0]).

Example

As an example, we are going to create a nice and impressive camera effect, which you can see e.g. in the first part of the Lord of the Ring: the transtrav. Basically, the idea is to combine a forward zoom with a backward traveling (or conversely), both controlled such as the point of interest keeps its scale in the image, while its environment scales up or down, depending whether it is nearer or more far from the camera…

Create a scene with a ground, and some objects laying on it. Add at least a Sun lamp (with sky/atmosphere effect, why not?), and some ambient occlusion.

Add a camera, place it as you like for the beginning of the transtrav (your “key” object should be more or less at the center of the picture, it’s easier to handle!). As we are going to do a “forward” transtrav, you should use a quite long lens at start. Go to frame 10, and insert a keyframe for both the location (and optionally the rotation) of the camera (Object Ipos), and its lens (Camera Ipos).

Now, go to frame 140, and move forward your camera to your key object. Insert another keyframe for its position, and adjust its lens until your key object have the same visual dimensions as at the beginning. Add a key to the Lens Ipo curve.

This won’t give you a fully perfect transtrav – to get such one, you would have to dive into trigonometric maths… But the result is visually quite satisfying! You can download the blend file File:ManAnimationTechsCameraExTranstrav.blend.