[rjsimmon]

the difference between a larger objective lens and the smaller objective lens is not brightness of image but field of view.

And that still increases brightness as more light is hitting the objective lens. Larger FOV is a function of the arc of the lens as well as diameter of the objective lens.

[Yo-Yo]

In optics theory, yes. In practice, the arc of the smaller objective is limited in order to cope with all of the other variables we both mentioned, so the larger objective will spread that increased light over a larger field of view, giving more or less the same brightness at the center as the smaller objective.

I think we're butting heads over theory vs. practice.