Diatoms: Isthmia nervosa - whole frustule

Images made through a microscope. All subject types.

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Beatsy
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Diatoms: Isthmia nervosa - whole frustule

Post by Beatsy »

Hi all

I thought I should try to curb my UV imaging addiction for a while, so here's Isthmia nervosa shot at 40x in visible light.

Isthmia nervosa-pmn.jpg
Larger

I confess I used visible light of the narrowband blue variety though! One small step at a time, eh? :D

Cheers
Beats

houstontx
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by houstontx »

wow amazing, looks like an SEM image!

iconoclastica
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by iconoclastica »

No, this image has a lightness, a tenderness and subtility that the coarse, plastic SEM imagery can never hope to obtain. Beautiful.
--- felix filicis ---

rjlittlefield
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by rjlittlefield »

Another wonderful image!

As usual, I would love to see the high res version in stereo. I have great hopes for the area on the left side where the two halves of the frustule overlap.

--Rik

Beatsy
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by Beatsy »

Thanks for your generous comments all.

On reflection, I'm actually not so pleased with the image posted (and that's not false modesty). Although the outcome is good for a 40x N.A. 0.75 objective, I could have done soooo much better if I'd used my 60x N.A. 1.42 (with blue light). I know that for a fact as I went on to do exactly that, which produced this...

Isthmia2-60x-BLU-4k-pmn 1.jpg
Do check out the image here which is sized to exactly fill a 4k screen (put your browser into full-screen mode to see the image displayed pixel for pixel). I'm very pleased with this version! The specular reflections around the edges (caused by illumination coming from behind the frustule) make for a nice enhancement too.
rjlittlefield wrote:
Tue Jan 14, 2025 9:09 am
As usual, I would love to see the high res version in stereo. I have great hopes for the area on the left side where the two halves of the frustule overlap.
Sorry Rik, you'll have to bear with me. I did stack a stereo pair for the 40x result but I don't want to publish that now. I didn't make a stereo pair from the 60x output and already deleted the stack images. I had a lot of other forms to do (in the same mount) and always delete source images after stacking. But I'll reshoot this Isthmia tomorrow and post the result on this thread.

Cheers
Beats

jmc
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by jmc »

Fab images Beats. I like the fact that you have got the front and back parts visible in the same image.
Jonathan Crowther

Lou Jost
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by Lou Jost »

Wow, astonishing!

Beatsy
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by Beatsy »

Thanks Jonathan and Lou.

Regarding the 60x stereo, I had a slight mishap and crashed the objective into the slide. The lens is fine (the front is spring loaded and didn't press too hard) but it caused the coverslip to slightly separate from the slide and left a couple of prominent black patches (of air?) under the diatom. Sigh. So pending making another mount, here's the 40x stereo. It doesn't really show much more IMO, but you may squeeze something out of it Rik...
Isthmia 40x stereo - pmn.jpg
4k version here

Cheers
Beats

rjlittlefield
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by rjlittlefield »

Beatsy wrote:
Wed Jan 15, 2025 2:32 pm
It doesn't really show much more IMO, but you may squeeze something out of it Rik...
For me this is not a "squeeze", it's more like a friendly hug that is returned in kind!

In the 4K view, zoomed in, I see obvious separation between the layers where the two halves of the frustules overlap.

I also see that the dark bands in the end sections appear to be caused by some structure inside the frustule, definitely subsurface with respect to the small roughly circular "lilypads" (areolae?).

In the end sections, especially the upper, I see what appear to be some small pores, aligned along the dark bands, that appear to go clear through the frustule.

Having noticed these aspects I can point to them in the 2D views, but I still cannot make sense of them there. Only in 3D is the structure clear.

This is another treat. Thank you for resurrecting it!

--Rik

Beatsy
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by Beatsy »

Hi Rik,

You interpreted the shape well. Yes, the linear-ish structures inside the frustule are thick ribs. However, the "small pores" are protruding "buttons" aligned over the ribs. They may or may not have unresolved pores in them. Probably do.

If you zoom into the middle of the left hand valve in the full-size 60x image, then pan up to the top, you'll see these buttons tipping back as you move the view up and around the curve. Squint a bit and you'll see 4 of them in profile on the top edge too. At least I think that's what it is.

Cheers
Beats

Beatsy
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by Beatsy »

I threw this pic together to illustrate a point on another forum but it's relevant here too. So...

Ishmia2 center crop-gigapixel_1--pmn.jpg

It's s a 512 pixel square cropped from the center of the original (5.5k wide) stacked image. It was rescaled to 1024 pixels square with no further processing except to add the inset. This inset is cropped from the marked region and blown up another 3x, also without further processing - so upscaled 6x in total from the original image.

I *think* I see rows of closely spaced pores (not visible in the downsampled 4k version I linked). I'll mount a few detached girdle bands to investigate properly - which is also the perfect excuse for using 365nm UV, again... :D

Cheers
Beats

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Re: Diatoms: Isthmia nervosa - whole frustule

Post by Scarodactyl »

The results are quite remarkable. Such fine detail!

rjlittlefield
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by rjlittlefield »

Beatsy wrote:
Thu Jan 16, 2025 1:09 am
However, the "small pores" are protruding "buttons" aligned over the ribs. They may or may not have unresolved pores in them.
I hear the words, but my eyes tell me something different. Here is a crossed-eye layout of the most definite example I see:
IsthmiaCrop01.jpg
In the center of this pair is a dark structure that visually extends from roughly the level of the lilypads to much deeper in the frustule, approximately the level of the dark fuzzy vertical band. Above that and slightly to the left there's another one. Above and below those, aligned with the vertical band, are other similar dark structures whose extent below the surface are not so clear, but which give me no indication at all that they protrude above the surface, in front of the lilypads. I simply cannot perceive these things as protruding buttons.
If you zoom into the middle of the left hand valve in the full-size 60x image, then pan up to the top, you'll see these buttons tipping back as you move the view up and around the curve. Squint a bit and you'll see 4 of them in profile on the top edge too. At least I think that's what it is.
I think I see what you're looking at, but I interpret it differently. Here is a marked-up crop.
IsthmiaCrop02.jpg

In isolation, the things that I've marked with blue-green arrows strike me as consistent with either pits or buttons. But I note that they do not occlude the lilypads that are close behind them in this image. If they stuck out as far as the things that I've marked with red arrows, then I expect they would occlude the lilypads. I have no idea what the red arrow blobs represent, but I am reluctant to read them as indicating that the blue-green things stick out so far.

Countering all that, by carefully searching the stereo for things that look like protruding buttons, I can find a few. Following is the best example I could find. Locked up in stereo, those things look like tiny lollypops with thin stems and larger heads. But then if I break stereo and study the images separately, I see so much accidental disparity that I'm not convinced the stereo impression means much.
IsthmiaCrop03.jpg

Oh how I long for an SEM view!

--Rik

iconoclastica
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by iconoclastica »

rjlittlefield wrote:
Thu Jan 16, 2025 12:43 pm
Oh how I long for an SEM view!
For what it may help (not exactly what you'd like to see)...

Screenshot from 2025-01-16 21-16-41.png
Screenshot from 2025-01-16 21-15-11.png
--- felix filicis ---

hkv
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Re: Diatoms: Isthmia nervosa - whole frustule

Post by hkv »

Absolutely wonderful! What a masterpiece of nature's engineering. Beautifully captured!

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