Difflugia

Charles Krebs · Post by **Charles Krebs** » Fri Nov 30, 2012 4:13 pm

A current marsh sample had a huge number of these testate amoebae. Two of the images (1 and 3) were photographed on a wet mount slide on the Olympus BHS using polarized light.

Then I tried something to get a little different "look" to the tests. They were placed on a slide with no water or cover slip, and photographed on the MM-11 microscope arrangement used for "dry" subjects (#2 and 4). Lighting was from above using two Ikea LED lamps through large ping-pong ball diffusers, with things set up to give a darkfield type of illumination. The tests I gathered measured about 300x180 microns (0.012x0.007 inches) in size.

Olympus BHS, Olympus S Plan Apo 10/0.40. Brightfield with partially crossed polarizers. 20X on sensor. 14 image stack. (Image cropped)

Nikon MM-11. Olympus LMPLFLN 50/0.50. Reflected light. 50X on sensor. 85 image stack.

Olympus BHS, Olympus S Plan Apo 4/0.16. Brightfield with partially crossed polarizers. 8X on sensor. 11 image stack.

Nikon MM-11. Mitutoyo M Plan Apo 10/0.28. Reflected light. 9X on sensor. 24 image stack.

curt0909 · Post by **curt0909** » Fri Nov 30, 2012 10:01 pm

In this case epi-illumination looks much better than transmitted in my opinion. Those are the best photos of a testate ameoba I've seen.

Litonotus · Post by **Litonotus** » Sat Dec 01, 2012 12:01 am

curt0909 wrote: Those are the best photos of a testate ameoba I've seen.

I agree.

Wim van Egmond · Post by **Wim van Egmond** » Sat Dec 01, 2012 12:50 am

Very nice to see this subject photograhed this way. I wonder how testae amoes like Arcella looks with this magnification. Or diatoms.

Wim

Ecki · Post by **Ecki** » Sat Dec 01, 2012 1:22 am

Very nice indeed. I prefer the reflected light images, too. How did you arrange the shells so neatly?

arturoag75 · Post by **arturoag75** » Sat Dec 01, 2012 9:28 am

Absolutely outstanding the second one..fantastic!

arturo

Jacek · Post by **Jacek** » Sat Dec 01, 2012 12:13 pm

As always, the sheer beauty

Charles Krebs · Post by **Charles Krebs** » Sat Dec 01, 2012 12:21 pm

Thanks for the kind comments!

Ecki...

Very nice indeed. I prefer the reflected light images, too. How did you arrange the shells so neatly?

Under a stereo microscope using a very thin insect mounting pin and a great deal of patience

. I actual started off with a larger number in the group but lost a few during the arranging process.

I was particularly happy the way the he 50X shot turned out (I've tried this a couple of times before with less success). The ability to control the light so that it accentuates the texture of the test is a big advantage over "normal" diascopic or episcopic microscope lighting. When the test is completely dry it does not photograph that well. It is similar to the way a dry shell, or piece of dry beach-glass takes on a "frosted" appearance. They look better wet. But too much water causes very troublesome reflections from the light source. This time the tests were immersed in a mixture of glycerin and water. When removed from the solution, the water eventually evaporated but a thin coating of glycerin stayed on the tests and provided the "wet" look.

Wim van Egmond · Post by **Wim van Egmond** » Mon Dec 03, 2012 12:13 pm

Very clever how you manipulated the humidity. For manipulating shells like this you could also try a cat's whisker. They lose them regularly so you often find them in the house. If you don't have a cat ask a friend who has one. The tip is very thin and the hair is strong. If the tip is to thin you can cut a part of it at the desired thickness. Where would we be without cats.

Wim

RogelioMoreno · Post by **RogelioMoreno** » Mon Dec 03, 2012 6:52 pm

Very nice and the idea to keep them wet is amazing!

Rogelio

carlos.uruguay · Post by **carlos.uruguay** » Tue Dec 04, 2012 4:07 pm

A marvel!!
carlos

Ecki · Post by **Ecki** » Tue Dec 04, 2012 11:58 pm

Charles,

Thanks for the explanation.