First of all, I would just like to say that I need to cut this video short so I can upload this fast on youtube. If I didn't cut it, then it would be 5 GB which will take me awhile on uploading this video.
Okay so I finally have the best setup to farm focus really really fast in Warframe. Now, I've tried different setups and missions and so far, this is the fastest. The mission was 15.24 minutes long and it enable me to gain 29,890 focus points in that short time!
So, basically what you need to do is take a Resonating Quake Banshee on Hydron/Sedna mission and do a 20 waves defense mission. Take note that to make the mission faster and easier, you'll need to team up with a Trinity for energy restore, a damage buffer like rhino or octavia and the other one is optional (you can go with a defensive warframe like frost).
P.S You need to do it with a team so that more enemies will spawn. Don't do it solo otherwise you'll not farm focus points like I did. Also, an affinity booster will increase the amount of focus points you gain in this mission.
This channel's purpose is to make the game grind a bit easier for you guys, so you can just enjoy playing your favorite game.