I am really confused with a problem relating to camera animation zooming into an object in a scene.
At about 100 frames into my animation I want to start zooming in and finish the zoom at frame 160.

But what happens when I play the movie back is that the zoom starts before frame 100 which is much to early. I have tried using the spline tool to break the keyframe at frame 100 but the zoom keeps happening. I have broken the spline on all of the camera's options e.g. perspective, focus, xyz orbit etc. but the result is still the same I really cant get this at all can anyone help please?

I'm no expert on animation, but here is how I think I would do it, perhaps someone has a better way. Before starting to make the animation, in the keyframe editor select all the frames for the camera, and set them to 'Linear Selection'. Open the 'Graph Display', go to the frame where you want to start the zoom and make it a keyframe. Go to the frame where you want the zoom to end and make it a keyframe, zoom the camera to the required amount in this frame. If the frame where the zoom ends in not the last frame, go to the last frame and make sure it is not a keyframe, ie select it and use the  Delete Keyframes "-" button on it.

@ lesbentley

Thanks for offering this advice Les. I tried your proceedure but the zoom still starts from the first frame of the movie and not from the frame where I need it to start.

One would have thought that doing a camera zoom from a specific start frame would work like dropping into a track with a music sequencer?

use les bentley's method above, it is good.

You can even do it without going to the graph.
Delete all keyframes on the camera

1. Make all camera keyframes linear (brown)
2. Move the timeline to where you want the zoom to start
3. Move the camera into place as you want it at start of zoom
4. Hit the "+" to establish a key frame
5. Move the timeline to where you want the zoom to end
6. Move the camera in to where you want it to be at the end of the zoom
7. Hit the "+" to establish a key frame.

Once you get solid control over the zoom based on les' advice, you can judge if the zoom is too abrupt and we can tell you how to do ease in/ease out....but better to first get control of the camera by making everything linear.

::::: Opera :::::

PXP be sure all keyframes are removed first, and that ALL actors on the camera are set for linear (brown).

@ operaguy

Hi operguy thanks for the additional clarification which made it completely clear for me. Both you and Les have helped me crack this thank you both so much.

Now I need to make the zoom work more smoothly and gradually?

For smooth and gradual, you ned to go into the animation graph and tinker with the graph's gradient. You might want to move to spline interpolation rather than linear, as well.

JonTheCelt