> Depth of field is determined by image size. Wide angle lenses tend
to
> exhibit greater depth of field because often images are smaller.
Henry
the images are 24 mm by 36 mm in both cases ... it's the
magnification that counts. :o)
(nit-picking I know but it is a slightly different thing)
If you set
> a 20mm lens and a 200mm lens to f/8 and set them both so each frames
you
> exactly from head to toe, depth of field will be the same. OTOH, if
both
> lenses are the same distance from the subject so the 20mm lens
frames the
> subject from head-to-toe and the 200mm lens frames the subject from
head to
> chin, the wide angle lens will exhibit greater depth-of-field.
So true: but the look of the pictures is very different.
Out-of-focus bits of the scene nearer the camera are, proportionately,
much nearer the camera for the wide angle than the 200mm. So not only
are they out of focus, they are bigger so too ;o)
But for some reason the tale "wide angle lenses give you more depth of
field" crops up once a month on every photo list. It is so stongly
rooted I don't suppose it will ever go away. Maybe it is easier to
understand than the highly mathematical concept of *magnification*.
Bob
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