Comments by "Lawrence D’Oliveiro" (@lawrencedoliveiro9104) on "" video.

Sampling theory comes into it as well: the ideal digital pixel is a point with zero dimensions*. Which is physically impossible. Because real-world sensors have a nonzero size, this has the effect of lowering the contrast of fine details close to the Nyquist limit. The cure for this is the “unsharp mask” filter, well-known to all users of photomanipulation software. *That’s right, pixels are not “little squares”.
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Science is about confronting the tough questions, not shying away from them. If the Earth is flat, are the other planets flat, too? If so, why do they look round?* If not, why is the Earth special? Remember, Galileo was the first human to see other planets (apart from the Moon) as round disks through his telescope, as opposed to dots* with the naked eye. ** Though I think Venus, when it gets close enough to us, gives a hint of being something more than a dot, in its crescent phases.
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I recall a story from Carl Sagan that the very first pictures from the Viking landers were accidentally “colour-corrected” to make the sky blue. Then when they were fixed later, this naturally fed some conspiracy theorists’ paranoid fantasies, that the landers had never actually left the Earth... But yes, I think all probes (or at least all landers) sent out with cameras also have calibration plates that the cameras can be pointed at for reference. That way they know what kind of colour correction to apply.
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A lot of images, e.g. many of those famous Hubble Space Telescope ones, are made at least in part from wavelengths other than visible light. So in these cases, yes, the assigned colours can become somewhat arbitrary.
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This is why quoting lens focal length doesn’t really make much sense, it is better to quote actual angular field of view. Then you don’t have to keep qualifying your numbers with the sensor size.
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