雾是“小猫脚上带来的”

绝妙的比喻，可惜找不到出处了，只知道是一首诗。希望以后能补上。

Edit on 17 June 2008: I found it here. :-)

Fog
Carl Sandburg (1878–1967)

THE FOG comes
on little cat feet.

It sits looking
over harbor and city
on silent haunches
and then moves on.

And another one: Link

Pearl Fog
Carl Sandburg (1878–1967)

OPEN the door now.
Go roll up the collar of your coat
To walk in the changing scarf of mist.

Tell your sins here to the pearl fog
And know for once a deepening night
Strange as the half-meanings
Alurk in a wise woman’s mousey eyes.

Yes, tell your sins
And know how careless a pearl fog is
Of the laws you have broken.

摄影上来讲，利用雾气，可以达到“使远处看起来更远”的效果。人的大脑觉察深度，某种程度上讲是通过较远物体细节的减少来达到的。雾抹去了远处树上的细节，产生了在近处和不远处物体之间较大距离的幻觉。