how do i change the destination were my video is captured?

i want to capture to a external hd

You go into preferences and change your 'capture scratch' folder. This is a global setting and will put all projects in the same folder unless you tell it otherwise at the beginning of each project. Depending on how you like to manage your projects and related media, this may or may not be important to you.

Some like to change their capture folder for each project so that it ends up in the same folder with the project's other assets. This allows copying one project folder to say, and external drive, for moving the work between two different systems.

-gb-

were is this pref. when i go there i see nothing that says anything about capture scratch folder

were is this pref. when i go there i see nothing that says anything about capture scratch folder

Final Cut Pro > System Settings > Scratch Disks

should the cache & the thumbnail be set to the external harddrive also? or does it matter

i am editing some hd dont have a very big hard drive on my macbook pro any advise would be apriciated.

new to mac
new to fce

also when i reconected my camera after connecting the hd my computer does not see it??????????
canon ah-1

The location of the cache & thumbnails is not critical; for organization, I keep them on the main drive, along with the autosaves, etc.. They don't take up much space. Also, if you delete them, Final Cut will recreate them, as needed.

After reconnecting the camera, try restarting FCP.