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On 10/11/2012 06:34, wrote:
> Maybe more like an astronomy question but I'll ask anyway.
>
> You know how when sometimes the moon looks like it's ten times bigger as it's
> just coming up or going down? I've heard that it's an optrical illusion. If you
> take a picture of it, does it show up in it's regular size or in that super big
> size?

It is actually very slightly smaller when near the horizon because of
two geometrical factors. It is one Earth radius further away, and the
effect of refraction in the Earths atmosphere compresses the sky
slightlty near the horizon so that is appears oval (as does the sun).

The problem is that the brain interprets what you see and near the
horizon tries to normalise it to being tree sized. I'd say the effect
was only a few percent for a trained observer but feels pretty real.

If you take the photos and measure them you will find the reality.

--
Regards,
Martin Brown