A few stentors

Charles Krebs · Post by **Charles Krebs** » Sun Dec 05, 2010 10:31 pm

Olympus BHS. Olympus 20/0.80 D Plan Apo UV (oil). Olympus 1.67X NFK. Canon 50D. DIC with electronic flash.

Olympus BHS. Olympus 60/1.40 S Plan Apo. Olympus 1.67X NFK. Canon 50D. DIC with electronic flash.

Olympus BHS. Olympus 60.1.40 S Plan Apo. Olympus 1.67X NFK. Canon 50D. DIC with electronic flash.

Mitch640 · Post by **Mitch640** » Mon Dec 06, 2010 5:43 am

Beautiful work Charles. Amazing detail. But as always, my head is now buzzing with all kinds of questions. Like does anyone know how the cilia work? From these shots, they look like they actually have a muscle analog inside each hair, rather than being controlled like a whip, from the edge of the "hairline". Did you notice if the edge of the funnel actually moves in a wave pattern?

Cactusdave · Post by **Cactusdave** » Mon Dec 06, 2010 6:52 am

Very beautiful photographs. They strike me as pretty tricky to take even with flash, as the depth of focus with the X60 NA 1.4 must be absolutely minute.

To reply to Mitch's question, there are plenty of references on the web that describe the function of cilia, depending on how technical you want your answer, but this is quite a nice little one page summary.

http://users.rcn.com/jkimball.ma.ultran ... Cilia.html

Mitch640 · Post by **Mitch640** » Mon Dec 06, 2010 7:29 am

Dave, a fascinating link. I am just an uneducated truck driver, but I can still appreciate the profound amount of knowledge that has been put together by a lot of people. Some of them right here in the forum. It's stunning, really.

Cactusdave · Post by **Cactusdave** » Mon Dec 06, 2010 9:13 am

That's one of the great things about this site. PhDs, MDs, truck drivers all welcome, you just have to be obsessed with trying to photograph very small things.

You may also find this link interesting as well as it is more relevant to ciliated Protozoa like Stentor, and explains a bit about those waves you can see in the motion of the cilia which have been frozen by the brief duration of the flash. Those are called metachronal waves.

http://cronodon.com/BioTech/Cells_motility_2.html

Charles Krebs · Post by **Charles Krebs** » Mon Dec 06, 2010 10:29 am

Dave,
Those are great links, thanks.

Mitch,
The "metachronal waves" are one of the more fascinating things to watch, especially on certain rotifer species like the ones here , here, and here. In fact that characteristic is what gave them their name. Also why they were (and often still are) called "wheeled animalcules".

Pau · Post by **Pau** » Mon Dec 06, 2010 10:40 am

Charles, the first two links doesn't work.

Beautifull images, as usual. Is the green tint in the first two due to DIC prism like in the NU's post?

Mitch640 · Post by **Mitch640** » Mon Dec 06, 2010 10:42 am

Charles, so you didn't work your way into taking world class images? You were born that way?

Those are really beautiful and from 2006. But, I had to go to the archive site to see the first two links;
Here,

And here.

Charles Krebs · Post by **Charles Krebs** » Mon Dec 06, 2010 11:00 am

Pau,

Fixed the links... had to add a "1" to the URL's since these are in the old site.

The stentors in the first two shots are in fact green, pretty close to what is shown. Since I worked from the raw files I just tried to retain the blue/green appearance observed. (But yes, the DIC will give greenish results at certain settings).

Cactusdave · Post by **Cactusdave** » Mon Dec 06, 2010 11:24 am

Charles The more I look at your pictures the more astonishing they seem! The high numerical aperture X20 Planapo oil is giving extraordinary resolution for an objective of that magnification, and must be a truly exceptional lens. The second image shows shows very fine granularity on what I assume is the surface of the pellicle of the Stentor. Do you have any idea of the size of the tiny particles visible? They must be close to the theoretical resolution limit. It would be nice to compare them with scanning electron microscope pictures, but I can't find any that are outside journal pay walls.

Tom Jones · Post by **Tom Jones** » Mon Dec 06, 2010 8:24 pm

Charlie,

If you keep this up I'm going to have to hit up my thesaurus for some more superlatives.

Your second photo is beyond awe-inspiring. Amazing detail, beautifully done!!

Tom

Charles Krebs · Post by **Charles Krebs** » Mon Dec 06, 2010 9:59 pm

Dave,

The 20/0.80 D Plan Apo UV is extremely sharp and bright, but it has one significant "issue". On certain bright edges it shows an unusual looking red/cyan color aberration that is tough to correct. I've experienced it with two different samples, and have communicated with Rene, and he has experienced the same thing with other samples. Too bad, because it provides an incredibly bright, sharp, viewing image. Here's a small part of the first stentor image. You can see what I'm talking about.

As far as resolution goes, I'm primarily after a good overall picture, so I don't necessarily pull out all stops in order to get the best resolution possible on a single detail (I generally need a little more DOF than that would yield). The 60/1.40 is an excellent good objective, and with that NA the very best I could ever hope for is a resolution of about 0.25 micron. Here's a small section of that second stentor shot (converted to b+w) with a few pairs of bars. The shorter bar represents one micron, the longer bar two micron. So I guess it's not too shabby.

Cactusdave · Post by **Cactusdave** » Tue Dec 07, 2010 1:35 am

That's a very nice demonstration Charles. You are completely resolving particles that are well under 1 micron in diameter and to say that's "not too shabby" is a piece of heroic self-deprecation!