Best editing codec working in Lightworks & Windows?

[rachelindeed]

Hi everyone! I'm fairly new to vidding and have been trundling along happily so far just learning to use Lightworks and getting the editing basics down. But now I'm starting to edge toward things like paying attention to picture quality and converting files into more editable formats, etc. I will read up on some of the previous posts people have shared (I see there was a recent discussion about how to deal with mkvs, which I've also recently been struggling with!), but my question for today is:

For vidders who work in Windows and use Lightworks to edit, what codec works best for your editing? And what software do you use to convert your various kinds of source files into that desired codec?

Thank you so much for any advice, it's much appreciated!