No more cellophane and duct tape, the Amscope dry dark field condenser has arrived! This specialized condenser has specially shaped optics and a built in dark mask to produce usable dark fields up to 600x. Im getting like 100x the contrast than the home made mask I made before. The condenser was not made to fit my microscope, so I designed and printed up a 3D adapter to make for a perfect fit to our microscope.

For this set of images, I collected about a half a teaspoon of lake water from the pond at the top of the waterfall. Algae was yellow green and growing well in this winter month. The fauna was surprisingly different than the summer mix. Some very strange colonial cone shaped organisms were found and loads of swimming diatoms were in abundance.

Above: Close up of the projection end of the Dark Field condenser. A bowl like concave lens is at top, with a dark internal black stop. The subjects are illuminated by a bright ring emerging from the edges of the lens where the glass is exposed. So the microscope sees a black disk - the subject sees a massively bright ring of light.

First a 150x transmission light image, showing the algal strands, hordes of tiny spindle shaped diatoms, and some of the cone shaped animals.

Same field with the new dark field condenser. The colors are true and brilliant, and invisible features appear across the field. The algae is gorgeous.

60x dark field view for comparison. A few bubbles are seen under the cover slip too.

At 150x, the colonial cones are attached to the algae strands. A smaller species of algae can also be seen here, showing as well the tiny individual cells.

Cones and diatoms at 150x.

It was exciting to see that the new condenser worked with the 40x objective as well. My old duct tape special NEVER worked at this magnification - about 600x equivalent. Note the spindle shaped diatoms swimming about. They move slow and seem to have no brains under control. They ram each other and can only go one way.

150x view showing different types of algae found. Note to the left of center there is some type of spherical animal that looks like a planet...

150x view of one of the larger algae strands. The colors in dark field are outrageous. Note how the colonial cones are in radial groups along the strand. No hint of the ribs on them at this power..

600x - swimming diatoms. They look like little torpedoes paddling about, their skeletons are composed of pure silica.

600x - Cones in colonies. Just a hint now at the ribs along their sides. The smaller algae strands now show good details.

Lets not forget the big algae strand! At 600x, now we can see amazing internal details. These features were not visible with transmitted light.

Cone groups at 600x. The "mass" of yellow on the right is a big ball of diatoms all glommed together. They did not move, therefore it seems that these were empty tests.

Same view at 600x in transmitted light. You can really see the difference between this and dark field above.

The view with the 100x objective with oil immersion has to be done in transmitted light. The dark field condenser is for dry objectives. (They actually do sell an oil dark field condenser but you have to put oil on both sides of the slide) The ribs on the cones are quite easy to see now here at 1600x.

Another set of cones with ribs. Hordes of dead diatoms are on the right.