Using binocular to observe Venus transit?

[mapguy]

A question for those of you who understand optics: in order to observe the Venus transit, my plan is to mount a binocular to a tripod, cover one of the lenses, and project the Sun out the rear of the other eyepiece, onto a white card. I've been practicing, and it seems like it's working: I get an image of the Sun that's about 4-6 inches in diameter, which I assume is big enough that I'll be able to see a black dot transiting across. But here's the thing I'm not sure about: am I seeing the entirety of the Sun's disk? Or am I only seeing the inner part of it, but not the outer limb? Or another way to put it: is my projected image round because the Sun is round, or only because the aperture is round? Thanks...

[Hornblower]

A question for those of you who understand optics: in order to observe the Venus transit, my plan is to mount a binocular to a tripod, cover one of the lenses, and project the Sun out the rear of the other eyepiece, onto a white card. I've been practicing, and it seems like it's working: I get an image of the Sun that's about 4-6 inches in diameter, which I assume is big enough that I'll be able to see a black dot transiting across. But here's the thing I'm not sure about: am I seeing the entirety of the Sun's disk? Or am I only seeing the inner part of it, but not the outer limb? Or another way to put it: is my projected image round because the Sun is round, or only because the aperture is round? Thanks...

It is the entire disk of the Sun. I observed the 2004 transit that way.