Guilty as Charged!
Anyway, to answer the question I have prepared some examples .. nice to see an EASY upload option here!
Thanks for the WELCOME . . thank you!
I prepared a w - i - d - e squiggly thingie in Paint Shop Pro and . . .
All in V7
Pic 1: Previewed. And there you can SEE the black bars above and below the graphic. I'm presuming that is what is meant by Vegas Resizing. Well If your project is "SET" to 4:3 as per my project then this is exactly what you will get AND what Vegas does - you told it too!
. . oh, if this is NOT what you mean ignore the rest of this . .
Pic 2: This show same in Pan/Crop, ready to have an area "used" to fit the Preview. Point being here is IF a still of any media doesn't fit - here 4:3 - then something HAS to give, either the Height or the Width OR sometimes both - yeah?
Pic 3: Maybe you can see the detail? But what I'm showing here is that I have adjusted the "F"rame to correspond with 4:3. This ALSO means I loose much of the picture, well yes it would!
Pic 4: And here you see the finished article WITHIN Preview. And yes, of course, you ARE seeing a magnified/zoomed-in portion of the Squiggle - well you would, wouldn't you? Fitting a Gallon into a Pint pot means that something has to be lost - setting up your Vegas project, directed by your video material - normally 4:3 or 16:9 - our Preview would be one of these 2 aspect formats.
Bottom line here is that if we do not want to re-size/re-crop/pan THEN you/I/we need to preset our stills to what ever we are preparing in Vegas - be it 4:3 or 16:9 or widescreen. Matching the aspect ration of stills that AREN'T in one of the aspect formats we use will mean that edges will be trimmed. Of course Vegas will "always" auto match - you asked it to fit everything within the ratio you set the project in. It is not a fault of Vegas, it is what is does best.
I hope this helps? Or maybe I've completely missed the plot here? Not the first time .. Lol!!