 | | From: | justbeats | | Subject: | Q: old diatom test slide designations | | Date: | 21 Jan 2005 02:26:29 -0800 |
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 | I recently acquired some more Victorian and Edwardian slides to add to
my collection. To my surprise (and delight) 30 (of 72) are diatomacea
including selected arrangements, strews from far-flung places and (the
subject of my question) 8 test slides.
These test slides all date to the 1920's and 1930's and besides
describing the species they are each labelled with "for 1/12" or
"for 1/25" (or other fractions). This must be related to the
objectives each test slide is best suited to - but how? What do the
fractional numbers mean?
Thanks
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| | From: | Aaron | | Subject: | Re: Q: old diatom test slide designations | | Date: | 23 Jan 2005 02:16:07 -0600 |
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| Hi,
I suggest that you look at the links to the Micscape website for
articles on diatoms used for evaluating microscope objectives. In
general the test diatoms are identified and the objectives for which
they are a test object. Your Zeiss optics should pass all tests with
flying colors.
Aaron
http://www.microscopy-uk.org.uk/mag/indexmag.html
http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artoct99/dwdiatom.html
http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artnov99/machdiat.html
http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artdec99/wvdiat.html
On 21 Jan 2005 02:26:29 -0800, "justbeats"
wrote:
>I recently acquired some more Victorian and Edwardian slides to add to
>my collection. To my surprise (and delight) 30 (of 72) are diatomacea
>including selected arrangements, strews from far-flung places and (the
>subject of my question) 8 test slides.
>
>These test slides all date to the 1920's and 1930's and besides
>describing the species they are each labelled with "for 1/12" or
>"for 1/25" (or other fractions). This must be related to the
>objectives each test slide is best suited to - but how? What do the
>fractional numbers mean?
>
> Thanks
|
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