Amoeba on the move, meets vorticellid

Images made through a microscope. All subject types.

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rjlittlefield
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Amoeba on the move, meets vorticellid

Post by rjlittlefield »

Video at https://youtu.be/FITvrTZqm90 .

You'll be seeing an amoeba approaching a vorticellid, maybe sizing it up as something to eat.

It's about 15 minutes of observation, speeded up 15X to give 55 seconds of excitement(?). No audio, sorry. :wink:

Image

This is my first public foray into video microscopy. Hhmm, first posting to YouTube also. And maybe the most interesting amoeba activity I've ever observed -- not that I've spent a lot of time observing. Lots of firsts here!

Cultured from a freshwater sample of shoreline debris, Columbia River near my home in Richland, WA.

The equipment was pretty modest: Amscope T490B trinoc microscope with 40X NA 0.65 achromat objective, recorded in full HD (1920x1080x30fps) on Canon Ti1 at about 56X on sensor (0.40 mm field width, says the stage micrometer). Post-processing in Camtasia, I cropped it to 1280x720 (0.27 mm field width) to eliminate extraneous parts of the field and get rid of an annoying shift in framing. I also bumped the brightness and contrast and toned down the added saturation that resulted from those. 15X speedup in Camtasia, produced in 720p for upload to YouTube.

Illumination was brightfield with "sleazy oblique illumination", to wit, I opened the condenser iris all the way and rotated the filter tray until its edge blocked about 1/3 of the objective aperture. I assume that a UGF filter would be better, but I didn't take time to make one of those.

All comments appreciated -- hope you find this interesting!

--Rik

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Post by zzffnn »

Nice video, Rik! I am your first YouTube subscriber then!

In my experience with my condensers, UGF works best at under NA 0.65. At or above that, a narrow COL ring nearly matching the back lens image of objective + sliding graduated ND (half COL) works better for balancing resolution/contrast. Each high NA objective needs a different matching ring though. For 40x NA 0.65, a 90-100x phase ring may work well.

1/3 crescent blockade has been my 2nd favorite. Sometimes, I close down condenser iris slightly to restrict outer periphery of the lighted back lens, then use sliding graduated ND to restrict the inner parts. That would provide more contrast, without significant loss of resolution.
Last edited by zzffnn on Mon Feb 13, 2017 11:59 am, edited 2 times in total.
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Bruce Taylor
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Post by Bruce Taylor »

Another subscriber, here! 8)

Nice work, Rik.
It Came from the Pond (Blog): http://www.itcamefromthepond.com/

Jacek
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Post by Jacek »

Nice :)

carlos.uruguay
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Post by carlos.uruguay »

Excellent video!

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