Re: Distribution of DoF

On Apr 20, 2:37 pm, Helpful person <rrl...@xxxxxxxxx> wrote:
On Apr 20, 1:28 pm, Monica Schulz <monica.sch...@xxxxxxx> wrote:



I'm not familiar with your notation, however I can explain what is
hapenning.
For an image that has no aberration, the depth of focus is equal
either side of the image. The depth of focus is dependent on the
numerical aperture and the wavelength of the light. Geometrically you
can consider a cone of light expanding equally either side of the
focus.
With aberrations the depth of focus will be different either side of
focus.

Yes, I understand that the depth of focus is the same on both sides of
the image plane but under the circumstances I noted the depth of field
is not equally distributed around the focus point. And that´s exactly
what I´m after.

Regards!
Monica

I'm not sure what you are asking. For an aberration free system near
the focus the intensity profiles are identical at equal distances
inside and outside of focus.

It sounds like the OP is asking about the depth of field, not the
depth of focus. The depth of field is distributed around the objects
in the field, not around the image plane: over what distance (in the
field of view) are objects in focus for a fixed image plane.

Depth of field is definitely not "symetrical" about the distance where
objects are perfectly in focus, since it is possible for this range to
extend to infinity.

Mark

.

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