Daphnia ephippia (with "resting eggs"); embryos

[Charles Krebs]

Still trying to get "up to speed" on the inverted TMD scope. You realize how "programmed" and automatic all your motions have become from working for years with one scope when suddenly you find yourself using something where the controls and sliders are all in different places.

Normally daphnia eggs hatch and develop in the female's brood pouch, where the embryos are very commonly seen (last two shots below).

When I first started looking at water samples I saw these odd objects but had no idea what they were. They are produced by daphnia and are called ephippia. At certain times of year, or when environmental conditions become difficult, daphnia will produce rugged eggs encased in a tough outer shell (ephippium). They develop in the brood pouch and are shed and released when the daphnia molts. They can remain dormant for long periods until growing conditions are more favorable. These eggs are usually called "resting eggs" or "winter eggs".


Nikon Diaphot TMD, Nikon CF 2X Plan Apo, Nikon D300


Nikon Diaphot TMD, Nikon CFN 10X Plan Achromat, Nikon D300, DIC


Nikon Diaphot TMD, Nikon CFN 20X Plan Achromat, Nikon D300, DIC



Nikon Diaphot TMD, Nikon CF 40X Plan Achromat, Nikon D300, DIC

[carlos.uruguay]

Thank you for this interesting information!
Excellent photos, as always

[Cactusdave]

These are really good, so jaw droppingly good that I had to wonder if I’m really using the same setup. Now I know any instrument you touch automatically gets sprinkled with a little of the ‘Charlie Krebs Magic Dust’ but a couple of questions immediately floated into my mind. One concerns the objectives you are using. I have been patiently accumulating Nikon plan DIC and LWD plan DIC objectives in the belief that these were the only ones which would give good even field DIC with the TMD DIC condenser. You come along with presumably non strain-free ordinary planachromats and get DIC as good as or to be honest much better DIC than I can get with the ‘right’ objectives. The second question is about illumination. The first picture of the resting eggs was presumably polarised light plus a wave plate or retarder of some sort. The second picture is just really great, stacked I assume? I couldn’t get that DIC colour or evenness without ‘Photoshop assist’ . I was intrigued by the very effective sense of directional lighting, was that achieved with very careful DIC tweaking or something else?

[RogelioMoreno]

Beautiful as always.

I am glad you are enjoying your inverted.

Rogelio

[Charles Krebs]

Cactusdave:

You come along with presumably non strain-free ordinary planachromats and get DIC as good as or to be honest much better DIC than I can get with the ‘right’ objectives. The second question is about illumination. The first picture of the resting eggs was presumably polarised light plus a wave plate or retarder of some sort. The second picture is just really great, stacked I assume? I couldn’t get that DIC colour or evenness without ‘Photoshop assist’ Wink . I was intrigued by the very effective sense of directional lighting, was that achieved with very careful DIC tweaking or something else?

The first picture utiizes is a real mismash of different lighting. A deep blue piece of plastic was placed over the condenser to get the blue background. Then some direct light was used onto the subject from both above and below the stage. The second image is DIC but with some considerable external light onto the subject from below the stage (otherwise the developing ephippium and eye went nearly completely black). This also gave a sense of directional light on the subject.

The 10X CFN Plan Achromat I have is the DIC version. But the others (including the 10X Plan Apo) are not so designated. I went through this with the Olympus as well. There, the "recommended" objectives for DIC were S Plan Achromats or D Plan Apos. But in direct side-by-side comparison with the S Plan Apos I could see no difference in DIC effect and the overall images looked best with the S Plan Apos. I have had other occasions with the Olympus metallurgical objectives (with reflected DIC) where again no noticeable difference was observed between the marked "NIC" objective and the non-marked. This is not meant in any way to be a blanket statement or in any way diminish the value of strain-free "POL" or "DIC" objectives. If I was doing serious analysis where critical polarization interpretation was essential I would want to use the "approved" strain-free versions. But for my uses, with my subject matter, if I can't see any difference I'm OK with it. And I have done enough direct comparisons that, for me and my work, (at least with the ones tested) I can't discern a difference. Obviously there are likely objectives out there that would be quite unsuitable for use with polarized light.

(When I started doing DIC I asked a very senior knowledgeable individual at Olympus if the S Plan Apos were OK for DIC, and his answer was to "just try them and see!")

Like I said I am still in the "playing around" mode with this scope. One thing I have noticed, and will look at more closely, is that I can get a much more even DIC background with the 10X if I raise the condenser higher than it's "proper" location. The overall DIC effect appears a a little weaker, but in some cases the end result looks better.

[Jacek]

Very nice

[Sumguy01]

Great pics.
Thank you for sharing the set up info.

[vasselle]

Very nice
Cordialement seb

[Cactusdave]

Thanks for the detailed reply. I really appreciate it. I'm impressed with your use of 'up from under' supplementary lighting on the Diaphot TMD. I have tried it it once or twice, and not got it right, but you have it spot on in that second image.
I completely agree that a try it and see approach is worthwhile when exploring mismatched objectives and DIC on the TMD. I have had some excellent results as I mentioned here, http://www.photomacrography.net/forum/v ... 615#178615 , but generally planapos have been disappointing. Planachromats and fluorites have worked better.

[piermicro]

Well done,