To E-X-P-A-N-D on Leo’s answer…
The footage shot with your DVX-100 is recorded onto the tape at a 5:1 compression. When you capture that footage, all you are doing is a digital file transfer, transferring the data from your tape into your computer. No loss of quality…but still compressed 5:1. There is no way to get more since that is what is on the tape.
HOWEVER…if you want to work in an uncompressed 8-bit or 10-bit timeline, if you have lots of text, graphics, green screen effects, then you can do one of two things: 1) purchase a capture card and capture the footage at the higher resolution (8-bit, whathaveyou) and work with that footage (recommended) or 2) capture the footage thru firewire as normal and drop it into an 8-bit uncompressed timeline and render it and work from there. The drawback to this is that you will have to render each time you make a change to the timeline interms of adding a clip or changing a clips duration…AND you will then have no way to get this timeline out to tape without a capture card. You couldn’t burn a DVD of the final, but if you need a tape, it is best to go with option 1.
Again, you wouldn’t be increasing the resolution of the source footage, but rather working in a timeline that allows for your compositing and graphics to be sharper and better.