I was editing 1920x1080/50i material in Vegas 8.0 using Excalibur multicam. Project properties were also set up for HD-50i(25fps).

After editing I noticed that rather than the straight cuts I was expecting, there appeared to be the odd disolve in there. At first I thought it was a problem with Excalibur (sorry Ed!) - but then looking at each edit there was definitely no fade curve - but deleting the second clip of the cut definitely resulted in the first one quickly fading to black. Then I noticed that last frame wasn't necessarily dimmer than the previous - it appeared that way because it was actually only showing every alternate line of the frame. I guess I actually made the cut half way into an interlaced frame so was only seeing one half. If I switched on Quantise to Frame and moved the cut to the nearest full frame the problem vainished.

What I don't fully understand though, is if I change the project properties to Progressive this also cures the problem even though the original footage is still interlaced?

I'm sure the above is obvious to many but may be useful to other new-ish-bies who might be sat there for an hour scratching their heads like I was!!!

Ian