Quote Originally Posted by holmburgers View Post
If the diameter of the aperture is equal to the focal length (1:1), there is no attenuation of light and nearly 100% will make it through (minus absorption in the glass of course). That's effectively the same as having no aperture. To prove it; take a reading of a scene like normal, suppose the meter reads f/5.6 @ 1/250th. Now, put your lens @ f/5.6 and place the meter at the film plane. At f/1.0 the meter will tell you that you need an exposure of 1/250th.

Now, as for a f/0.95 or larger aperture actually magnifying or amplifying the light, think about this; the image formed by the lens is significantly smaller than the subject that you're photographing. With that in mind, if you can pack the same amount of light into a smaller area, you can indeed amplify the light at the film plane, relative to the subject.

No one seems to believe me on this point, but the reality is that physics proves it. The 2nd point you make about amplifying light is a little harder to wrap my head around, but I believe there's an equation out there somewhere that can show this as well. (I gotta be careful touting the "math", because if you asked me to do it, I'd have trouble...)

Here, the first two equations on the wikipedia exposure value page (http://en.wikipedia.org/wiki/Exposure_value) should be able to prove it if you feel like plugging in some numbers.
When you said take the meter reading at the scene like normal, how do you do that? Using incident or reflected light meter? Same thing when you said meter at the film plane, incident or reflected. And if measuring reflected light at the film plane how would you do it?