Gammarus spp In Different Lights

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KurtM
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Gammarus spp In Different Lights

#1 Post by KurtM » Wed Dec 05, 2018 12:25 am

I have been fooling around with mini-aquariums again, and for today's amusement tried my hand at imaging a larger critter than I normally tackle: a Gammarus. I'm not up on my amphipod crustaceans, and there are a zillion of these things, so I leave species to the experts. These images are stitches of 6 images each, the source images are single frames, all shot through the 4x objective on the Diaphot TMD. The result are in bright field, DIC (kinda, the 4x doesn't have a matched prism), simple POL, and POL with 1st order red compensator.

The POL images highlight musculature, of course. Overall length from stem to stern is right at 4 mm.
Attachments
01 Gammarus spp bright field 4x.jpg
01 Gammarus spp bright field 4x.jpg (108.43 KiB) Viewed 1004 times
02 Gammarus spp DIC 4x.jpg
02 Gammarus spp DIC 4x.jpg (102.51 KiB) Viewed 1004 times
03 Gammarus spp pol 4x.jpg
03 Gammarus spp pol 4x.jpg (53.69 KiB) Viewed 1004 times
04 Gammarus spp lambda 4x.jpg
04 Gammarus spp lambda 4x.jpg (86.23 KiB) Viewed 1004 times
Cheers,
Kurt Maurer
League City, Texas
email: ngc704(at)aol(dot)com
http://sawdustfactory.nfshost.com/microscopes/
https://www.flickr.com/photos/67904872@ ... 912223623/

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75RR
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Re: Gammarus spp In Different Lights

#2 Post by 75RR » Wed Dec 05, 2018 6:19 am

Nice set! Like the mix of illumination techniques.

4x does have a nice depth of field!
The result are in bright field, DIC (kinda, the 4x doesn't have a matched prism) ...
What prism did you substitute for the missing 4x one?

Have you seen Cactusdave's posts on mismatch DIC objectives?

https://www.photomacrography.net/forum/ ... hlight=dic
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

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rnabholz
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Re: Gammarus spp In Different Lights

#3 Post by rnabholz » Wed Dec 05, 2018 11:59 am

Interesting fellow, don't believe I have ever seen one before.

Nice study in illumination effects too.

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KurtM
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Re: Gammarus spp In Different Lights

#4 Post by KurtM » Thu Dec 06, 2018 2:05 am

Rod, I'll bet you have seen these guys before, probably took 'em for some sort of insect larvae zipping around. I believe they're fairly ubiquitous in FW pond/river/birdbath samples. Big enough to be easy naked-eye visible, this one is 4 mm long and as I'm sure you know that's 1/8" ... and we old draftsmen typically made the lettering on our drawings 1/8". For whatever reason, lately I've been taking increasing interest in the larger denizens of FW samples, particularly cladocera. This amphipod, plus a few of his buddies, were in a sample I was about to discard.

75, you bet I've seen Cactus Dave's article, and have studied it quite a lot as I'm sure you have too. I also once saw where Charles Krebs mentioned occasionally mismatching prisms on purpose to get improved DIC effect on the camera sensor. So I've learned to experiment, even trying prisms upside-down where possible (Zeiss but not Nikon). In the TMD's case, the prism for the 10x lens works best with the 4x; the others present an increasingly narrow, abrupt extinction band.
Cheers,
Kurt Maurer
League City, Texas
email: ngc704(at)aol(dot)com
http://sawdustfactory.nfshost.com/microscopes/
https://www.flickr.com/photos/67904872@ ... 912223623/

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