Hi,

See http://en.wikipedia.org/wiki/Dark_field_microscopy
Sometimes, dark-field image is useful to inspect surface uniformity after
etching.

Oray Orkun Cellek

On Sat, May 2, 2009 at 4:13 PM, Evelyn B  wrote:

>  Can anyone tell me what the purpose/application of dark field illumination
> is?  Can anyone recommend a good site or paper that explains the concept
> and
> shows applications?