I have managed to compress my 3-screen video essay into a HD format, and upload onto Vimeo in HD – so the textual element is readable full-screen. Here is the link:
I made the essay at 1920×1080 pixels using Apple’s PRORES422 Codec (although it is in fact made up on 3x Dv-PAL 4:3 screens at 90% of original size). I compressed it for upload as a H.264 movie, based on the Quicktime 7 LAN Download Present in compressor. This will preserve the data rate, but allowed me to go into the setting and increase the frame size. Because the video has a goant black bars top and bottom, the quality is still good.
The text is using a free Teletext font I downloaded (its called Mode 7 – free from the internet) – and I think it’s about 20 point size although would have to.
As Vimeo essentially compresses to 1280×720 in any case, there was no benefit for me having compressed it in 1920×1080.
To compress your own video in HD, made sure it is made in 16:9 aspect ration – then in compressor, apply the Quicktime 7 LAN H.264 preset in the Internet Downloads for Quicktime 7 section. Once applied, select the preset that has been applied to the movie, then in the settings box below, go to the pixel dimensions section, and manually set it to 1280×720 pixels (using square pixel aspect ratio). Vimeo will then not re-size your movie any more – and it should look nice – but bare in mind if you have a lot of detail/movement there may be slight quality loss as it limits to the data rate for the LAN preset.