and about the crop lens needing to be a .95 was it? to be equivalent ? now why is that ?
wouldn't that make them not equal as the crop sensor lens is letting more light in? wouldn't it ?
You're correct, F2 is F2 for exposure purposes.
He's trying to calculate what the equivalent focal-ratio would need to be to achieve similar depth of field at the same physical distance from the camera to the subject on a smaller sensor, relative to a full frame equivalent. And he's trying to calculate basically the focal-ratio relative to surface area for amount of light. He's just trying to steer the topic away because from his full frame can be "just as small" speech.
But remember, he's not a numbers person. He can't be bothered with "fancy numbers" on little lenses. Like F0.95, or F1.2 or something. Just like he's not a numbers person, but wants to make sure you know that 35mm isn't really 35mm and F2 isn't really F2. But nevermind all that! It's just his red herring bait.