Spirogyra Feathered darkfield stop illumination.
Spirogyra
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Spirogyra
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA
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Spirogyra
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
Mike
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA
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- Location: Lund, Sweden
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Feathered stop
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
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