How to make it look like an iPhone

So, i record something with my iPhone or iPad; then i tinker with it in FCP and export it..but during the export a black border is added...I embed these videos into an iPhone or iPad frame in Keynote and they fit perfectly without an edit..

When I edit in FCP and export I end up with black borders...does this make sense to anyone??

So, how do I export iPhone footage to look like iPhone footage without the humungous black slabs either side??

Black borders where? Post screen shots. What are the exact specs of the media and your project properties?

What's that your project with the iPhone video in it? What are the specs of your media exactly? Please give complete information. Create a custom project size that matches the specs of your media.

Yes, this is an iPhone video brought into a custom project...but to me the project only changes the format from 1080 p or i to other choices...such as 720 hd..is this what you refer to?

This I tried and I still get the black borders on export...

Are you using an old version of the software? What version is it?

Version 10.1.3 I saw this and thought this would only dial up or down the resolution..perhaps I am being a muppet here..

Do you understand what I am talking about? I think I am not describing this clearly..I could fire up a weber or GoToMeet and show you? or is that verboten?

If you select custom you can dial in whatever horizontal and vertical resolution you want. What are the specs of the media? You've imported the iPhone video. You can get the details of the media from the Info inspector in FCP or from the inspector in the QuickTime player.

Eureka...now I get it...perfect help and thanks for sticking with me