Rogerdee, I've only done 1 film and so I hope to have enough info to help ya out, but luckily my only film was in widescreen. So the answer to your question is what happens when you put a square into a rectangle?
You get some empty space left over.
I.E., black bars on the left and right of screen.
How do you fix that you say? Simple, have the image stretch to the new video size.
What? The image looks stretch? Noooo..... really?
I say, don't force a square into a rectangle, but force the rectangle into the square.
Well now, you just need to first take your square and place a rectangle over it. Make sure the length of the rectangle is no longer than the length of your square, and any exposed square showing, just cut it off. Now you have a rectangular picture and you've lost some of the original picture. All in the name of widescreen.
Warning, technical jargon below:
Roger, you used an aspect ratio of 1.78. My first and only film was in 2.20 for the video, but with the black bars for subtitles, it was in 1.78, just like yours. File resolution was 512x384, which if you do the math is 4:3 not 16:9, but I used rectangular pixels to achieve a 16:9 ratio.
