Read the rules
When submitting a video to a convention, one must be very careful to
read the entry rules so that you are submitting in a format that they
will accept. It is very important to follow these rules.
Follow these simple rules of thumb when deciding how to submit:
1) If they specify a preferred format make sure your video is in that
2) If they do not specify a preferred format and instead accept a wide
range of formats then submit using the highest quality format they
allow. If they allow a lossless format like HuffYUV then send them a
HuffYUV master on a DVD-R or, if they allow it, split across several
CD-Rs. This is especially important if they are going to be re-encoding
everything they receive anyway so that as little quality is lost as
Does the convention prefer MPEG2?
Most conventions do prefer this format. Scintilla has written a useful guide on encoding your video to mpeg for conventions, which you can read here.
We can't guide you through the process for every single convention
Different conventions have different rules, and request videos in different formats, different resolutions, different framerates, etc. If you have made it this far into the guide, I really have faith in you that you don't need to have your hand held every single step of the way, and you can figure this stuff out on your own by this point. If the convention doesn't prefer a DVD-compliant MPEG2 file, then it would probably be a good idea for you to look over both the guides on encoding for online distribution, as well as the guides on encoding DVD-compliant MPEG2. Between these two, you should be able to figure out how to get things into the highest quality format that the convention will accept.