MOV to MKV

I have MOV video (FULL HD) recorder with Canon, and I want covert that video in MKV to have smaller video file but in good quality. I try convert that video with Handbrake, but I always get same video quality. I try with 5000 Avg Bitrate, and 20000 Avg but still same video quality. Where is the problem? Or you can suggest me some other converters.


Thanks!