UPDATE April 2018. I just can't get back to updating this--haven't played Warframe in a while and there have been so many huge changes. If someone still playing Warframe would like to update this, please ask me and perhaps you can make your own solution using the information here that is still accurate. Needed updates include: Amounts of focus gained per day, Eidelon lenses, focus tree changes and unlocking, and a few others.UPDATE DECEMBER 2017.
To get the achievement, you must unlock the start of each node in one Focus skill Tree
There is also a Mastery Rank requirement for some of the nodes in the Focus Trees. Mastery Rank 6 is the lowest that will clear 3 Focus Trees: Naramon, Unairu, and Zenurik, otherwise you need MR 8 or 12!
For those wondering, here is a picture that shows what the Mastery Rank locked node looks like(Thanks to Tukaitaua):
Focus Skill Trees are basically skill/ability/power trees that unlock special abilities you can activate similar to your Warframe abilities.The Focus area of Warframe is unlocked by completing the Second Dream quest.
In order to unlock the Second Dream quest, you have to complete the prerequisites:
Mastery Rank 3, the Natah Quest, and the Stolen Dreams quest.
The Natah quest can be started by scanning one of the blue sentients in one of the Underwater tileset missions on Uranus.Focus is a type of XP gained in Warframe missions, that is only gained on Rank 30 Warframes or Weapons.
The Focus XP can then be put towards different upgrades in the Focus Tree you've chosen. You can gain multiple types of Focus at once, but each type of Focus can only be put into the Focus Tree it matches.Focus is gained by equipping a Focus Lens or Greater Focus Lens on a Warframe or weapon.
The Lenses can be equipped when the Warframe or weapon(WoW)
are at rank 30. If you forma the WoW, the Lens will not be active until you reach rank 30 again!
You can only equip 1 Lens or Greater Lens on any single WoW at one time. Replacing an equipped Lens will destroy it!
You can equip a Lens on your Warframe or weapons all at the same time though for maximum Focus gain.
To equip a Lens, got to your Warframe's current Mods loadout screen, then click in on the right stick.
A regular Lens gains Focus at the rate of 1.25% of the regular XP you gained on the WWoC.
A Greater Lens gains Focus at the rate of 1.75%!
For some time now regular Lenses have been available as sortie mission rewards, and Greater Lens blueprints have been available in the market for 200k? credits, which require 4 regular lenses to build a Greater Lens. However, the Greater Lens itself costs only 40 plat making it generally worth it to just buy a Greater Lens with plat if you can afford it.
The Focus Trees can be confusing at first; make sure to take some time to research which tree you really want for it's abilities.
The Focus required to completely unlock the first level of each node for each tree according to the warframe wikia: http://warframe.wikia.com/wiki/Focus
is right here:Note: Each tree costs 50,000 Focus to unlock if it is not your starting Focus choiceNaramon Tree requires 485,000 Focus All nodes unlocked by MR 6!Unairu Tree requires 485,000 Focus All nodes unlocked by MR 6!
Madurai Tree requires 565,000 Focus All nodes unlocked by MR 12.
Vazarin Tree requires 635,000 Focus All nodes unlocked by MR 8.
Zenurik Tree requires 545,000 Focus All nodes unlocked by MR 6!The daily focus cap limit is 250k per dayThe Naramon and Unairu Trees are definitely the best choices at this time since they have 50k less focus required to complete the base level of each node!The Zenurik Tree is the best known choice at this point if you won't be increasing your Mastery Rank much!
(Thanks BIGB EC!)
(Vazarin has a useful ability called Mending Tides which allows you to pick up allies from a distance, and Zenurik has an even better ability called Energy Overflow which brings in energy at up to 4 per second)
It's highly recommended to use a Greater Lens on a WARFRAME, not a weapon, unless you have extra platinum or lenses. I personally got over 1 million Focus with a Greater Lens on Ember/Ember Prime. The World on Fire ability collected a LOT of focus over time. Choose carefully where you put your lenses however, as some Warframe abilities don't even count for Focus. Such as Valkyr's Hysteria mode, unless they've updated it, didn't count for Focus at all.
There are a few ways of tricking the game to get max focus, but they seem to get patched regularly. YouTube usually has video's of new ways of getting lots of focus easily!
There is also a new thing in the game that gives you 6x Focus bonus gain; called Convergence, it'll spawn randomly in the mission and has the symbol of a poison/nuclear facility. If you pick it up, it lasts for 45 seconds, and will respawn in missions periodically. It only counts for the person who picks it up, but will multiply by 6x any focus gains you get in that period!
Here is Hybrildchld's great method for getting Focus with his Rhino Prime: