[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.

[rjsimmon]

Theory and practice are essentially the same as physics limits how much of an arc the lens can sustain without distortion. The practical side of building high quality lenses comes in how much the customer is willing to pay for something that simply transmits light. Zeiss, Leupold, Swarovski, all command a high premium because they turn out high quality glass. But Bushnell, Nightforce, and Trijicon are competing quite well because they balance cost with lens quality.

What they all do is coat their lenses. This does several things: -reduce glare -restrict ultra-violet -reduce fog (among other things). But they all desire the maximum amount of light to be transmitted. They do this by increasing objective lens diameter. The fact that this increases FOV is not lost on any of them, but to say that it does not increase brightness simply defies physics. Everything we see, if it is not a projected light source, is reflected light. The paper you read, the trees, the animals, EVERYTHING is reflected light and a rifle optic is designed to transmit the maximum amount of light that is there.

[rjsimmon]

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

Forgot to add, I do not thing we are butting heads but rather having a fantastic discussion as God intended.