>None of the previous replies has mentioned the depth of field trade off one
>suffers when increasing magnification. I am under the impression that
>because 63x objective provides greater depth of field one can afford fewer
>steps along the z-axis. I assume this saves time in imaging and analysis
>and, obviously, memory.

>Do these assumptions hold or is my confocal inexperience showing?

Sorry, these assumptions do not hold.  Like resolution, depth of field
is solely a function of numerical aperture (that is, the angle of the
cone of light entering the lens).  So both lenses, being both NA 1.4,
will show the same depth of field.  In fact that is why many confocal
microscopists like NA 1.4 lenses of x63 or x60 - the give a wide field
of view with a narrow depth of field (ie good Z resolution).

                                                Guy Cox

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