changing an aspect ratio
 

Yes, another question. Its a learning curve all this editing you know. I might have mastered Premiere in about 3 years!

If I have an aspect ratio of 16:9, or 1:78.1 I believe it is also known, how can I change it in the following ways:

1) To take the .avi file after capture, and slightly crop the 16:9 image to a 1:85.1 cinema format, so that on a widescreen TV there is a slight letterbox effect.

2) Take pure 16:9 video and make a 4:3 standard version that will display as a letterbox image on a standard TV, ie, no cropping at all, 100% of the image but zoomed out like widescreen films shown on TV with full letterboxing to retain 100% of the original image.

Can this be done in premiere? After Effects?

im not sure exactly what your question is....

Do you want to know if any of the above is poosible?

well.. as far option 2) i would just take in your 16:9 in premier
and do a fit to aspect ratio to 4:3. In After Effects you can just
set up a comp to 720x480 and import your 16:9 video and just scale it
down untill the width of your 16:9 image is 720 pixels.

for 1) you can do this by cropping the image in premier according to the 1:85.1 aspect....this wil create the black space on the top and bottom for you 16:9 image.

1. add small black bars over your footage to get 1.85. I use After Effects
2. Create a 4:3 project in Premiere. Import your 16:9 footage the timeline, right-click and select maintain aspect ratio. That will auto letterbox it to 4:3

Very easy.