Re: features visible at low magnification are not "clear" at high magnification

Hi Gary,

Doubtless you are correct. However, in this case, I get the feeling
that the equipment to sputter coat the specimen is just as
out-of-reach as the darkfield epi- objectives. I wonder if another
type of coating might do the same thing, say a thin coating of paint
or perhaps a dilute carbon balck suspension.

Aaron

On Wed, 28 Dec 2005 17:38:04 -0800, Gary G <see.signature@bottom>
wrote:

>On 18 Dec 2005 17:37:39 -0800, "sanjiv"
><shrivastavas@xxxxxxxxxxxxxxxxxx> wrote:
>
>>Dear microscopist,
>>
>>I think i have a relatively simple problem for the experts in
>>optical microscopy.
>>
>>I'm looking at indentation in hard ceramics [opaque material] using
>>simple optical microscope with x10,x20,x50,x100 using yellow light,
>>observing in reflection mode.
>>
>>The problem I have is at low magnification x10 around the indents a
>>ring like feature is visible, however at high magnification x50 or
>>x100 the features is not visible. The lateral size of the indents
>>ranges from 30um to 200um. measurements by different techniques
>>(AFM) the vertical depth of indents range from 2um - expected 15ums.
>>The ring like features ranges in height from few(10-50) nanometers
>>to about 1ums.
>>
>>
>>I would appreciate comments, literature, references etc. explaining
>>this effect.
>>
>>since, images can not be posted, i would gladly give images for indpeth
>>response.
>>
>>
>>thanking you for the help.
>>
>>Warm regards
>>Sanjiv
>
>If you can tolerate destructive action on your sample, sputter coating
>with 60A Au/Pd will make the specimen look quite different under LM.
>
>Gary Gaugler, Ph.D.
>Microtechnics, Inc.
>Granite Bay, CA 95746
>916.791.8191
>gary@microtechnics dot com
.