Why Hydroid's Tentacle Swarm doesn't give affinity?

[tprx]

When you kill enemies with Hydroid's Tentacle Swarm, you see the +x affinity on screen, but when you finish a mission, you have close to no affinity earned. Is that intended?

Now I use Hydroid mainly for farming with Pilfering Swarm, so it's not much of an issue. But I've been wondering for some time now. Does other frames fourth ability give no affinity as well?

edit: Forgot to ask: I currently have no focus lens on Hydroid. Since his fourth is my main source of damage, and since it doesn't seem to give affinity, is it worth it to equip a lens? In other words, does a lens equiped on Hydroid gives any focus at all or is it a waste?

Edited June 26, 2018 by tprx

[Naftal]

You mean Hydroid is not getting affinity itself or your weapons are not getting affinity?

My Hydroid gets affinity just fine from killing with tentacles.

[-QUILL_PETER-]

100% of affinity from frame kills goes to the frame.

[tprx]

Oh! Since my Hydroid is maxed, I don't get anymore affinity. So if I install a focus lens, it would accumulate focus normally. Thanks guys :)