Spirogyra

Images made through a microscope. All subject types.

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Olympusman
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Joined: Sun Jan 15, 2012 12:31 pm

Spirogyra

Post by Olympusman »

Spirogyra Feathered darkfield stop illumination.

Image
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA

ChrisR
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Post by ChrisR »

Very nice lighting. What magnification is it at?
Chris R

Sumguy01
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Location: Ketchikan Alaska USA

Post by Sumguy01 »

:smt038 Very nice.
Thanks for sharing.

Olympusman
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Joined: Sun Jan 15, 2012 12:31 pm

Spirogyra

Post by Olympusman »

Shot with a 20X objective. The spider darkfield stop I made for this objective enables feathering the stop to result in a more three-dimensional rendering as seen in this shot.

Mike
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA

micro_pix
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Post by micro_pix »

Excellent! Great depth effect.

viktor j nilsson
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Location: Lund, Sweden

Post by viktor j nilsson »

Beautiful, and interesting. Could you explain this feathered darkfield stop in more detail? Perhaps show a picture? How is this 'featherin' achieved - polarizing film?

Olympusman
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Joined: Sun Jan 15, 2012 12:31 pm

Feathered stop

Post by Olympusman »

In photographic lighting, a feathered edge from a light source is attained by placing a card between the light source and the subject so that there is a diffused edge on the lit area.
In the case of a feathered darkfield stop, the spider stop is swung under the condenser so that there is a transitional zone between the bright field and the dark field. In this image you can see a darker area on one side of the spirogyra and a brighter one and on the other side a brighter side. This is also the technique I have been using for Rheinberg illumination.
The effect is almost like COL illumination in which a condenser is shifted off-center to somewhat sidelight the specimen, resulting in the three-dimensional effect.

Mike
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA

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