If you do go in for recording synth playback yourself, here are a couple of notes:
:: When moving through a synth, you are not using the highest resolution of the photos available (and there is nothing we can do about this as users), so there will be an upper limit to the effectiveness of higher resolutions that video can be recorded at. Source: asdf
:: The resolution that you load the synth at is the resolution that it will continue to render at after you have changed the size of the browser window (by maximizing, restoring, shrinking, or using fullscreen) so when the goal is recording a synth's playback in the highest resolution, you'll want to:
1: use a monitor with the target recording resolution,
2: enter your browser's fullscreen mode [F11] on the synth's view page first and refresh the page once so that the viewer is then rendering at the monitor's resolution, then use the viewer's Fullscreen to hide the left icons.