The size of the file will also depend on the video encoder that is used and the content of the video itself (50mins of a visual novel game would be much smaller than 50mins of an first person shooter, for example).
1.6 - 2.2 GB for a 50 minute recording is actually quite small and definitely at the low end in terms of what you should expect. But 26 - 28 GB is much bigger than anything we're seeing. As a rough guide, when we record for that length of time at 1080p, 60 fps, we tend to get anything from 5 - 15 GB depending on the game.
All we can suggest is to use the Send a Problem Report option on the Support tab to send us a report next time you get a huge file and we can check the log files to see if there is anything unusual going on.
