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Aperture

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Buy the right telescope, not the biggest one

Which telescope showed this?

Five eyepiece views a day. Each was made by one of three telescopes under the sky stated above it. Pick the aperture — then see all three side by side.

How it works
  • Every view is computed, as in the simulator: the true field, the brightness the exit pupil allows, the detail the aperture resolves. Nothing is retouched.
  • The three telescopes share a focal ratio and an eyepiece, so the exit pupil is the same; only the aperture — and the magnification it implies — differs.
  • The three always show the target on three different levels, from “not visible” to “detailed”. Those levels are observing heuristics, not optics.
  • A new puzzle every day at 00:00 UTC, the same for everyone. No account; your streak stays in this browser.

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