How do I flag my SSN?

How does my telescope "see through" a flag?

• I was aligning the spotter with the eyepiece to an antenna on a faraway mountain and a nearby flag was fluttering in-between the scope and the antenna. The flag obscured the antenna in the spotter about 80% of the time, however, in the scope, the antenna was visible 100% of the time! I could see it through the flag. The flag was still there, but the flag was transparent! So cool. Is it because of the light-gathering power of the 11"? Like does it just suck the light through the flag? I would love a good explanation! thanks!

• Answer:

  If the flag does not cover all of the aperture of the telescope, then the uncovered part will deliver an image of the faraway mountain, but the flag will be out of focus and won't appear in the image. If the flag had holes in it that were substantially larger than a wavelength of light, then that residual small area of aperture would still deliver an image, and it wouldn't matter if the flag were fluttering and the holes moving around. We normally don't see these effects with our eyes, because the aperture of the human eye is so small (only 7mm).