I like using MPEG streamclip for my transcoding.  It runs pretty fast and is a free download from the web from this link. It is a bit involved but just follow along with the pictures and you will not have to render any sequences upon output.

In MPEG Streamclip go to File, and down to Open Files.

Find your file and click on Open.

Now click on File and go to Export to QuickTime.

Click on the Compression pull down menu and select Apple DV/DVCPRO - NTSC

Then, to make sure it stays at a 16x9 aspect ration, click on the Options button and select 16:9.

On the Quality slider, drag it right to 100% (or less if you want cruddy looking video).

In the Sound selection, you can leave it on Uncompressed, Stereo and set the rate to 48 kHz

It probably defaults to a 29.97 frame rate, but type it in anyway. It usually will default to the 720x480 frame size as well, but check it. The above settings are the default but make sure your settings look like this.

Yay!  Now it is time to make your transcoded video, select the Make Movie button.

Name it, put it where you can find it and select Save.

OK, back to FCP. You will want to create a new project with Easy Setup.  Remember that everytime you change the easy setup settings it only applies to new sequences, not existing sequences.  I usually start out by deleting the default sequence and the go to Easy Setup and the create a new sequence.

Set the settings as you see here.

Set the settings as you see here and select Setup.

Go to the File menu and select New and then Sequence.

Import your transcoded file and drag it to the timeline and LOOK!  No render bars!

If you look at your canvas window it should be a 16:9 aspect window.  Depending on your camera you may or may not have those annoying 4 pixel pillar bars.  I usually just scale up the video 6 percent to make them disappear.