Diatom: A complete frustule of Isthmia nervosa

[Beatsy]

Hello all

Here's a focus stack of Isthmia nervosa shot with an Olympus 60x N.A. 1.42 objective under brightfield illumination. I used blue light (450nm wavelength) to gain a bit more resolution. I'm rather pleased how this one came out - lots of detail for pixel peeping



There's a larger 4k version (without scale bar) here

Cheers
Beats

[Rene]

Hi Steve, this is an absolute stunner!

I don't do much in image manipulation, but is it possible to lower the brightness of the valve structure that is laying under the girdle? It might make the view of the girdle structure more dramatic!

BTW, is this single frame stack or stitched as well?? Wow!

Best, René

[Michael K.]

Hello Steve,

The picture is great. I like the details, I inverted it for testing purposes. I have the impression that I can see more details.

But maybe it's because I like to invert my own pictures. It's definitely a matter of taste.

Regards
Michael

[sushidelic]

Hey Steve,

a beautiful picture! The 60x/1.42 is also my favorite objective for high res work.

Best regards,
Michael

[Beatsy]

Thank you all for your comments, much appreciated.

Michael K,
I occasionally use darkfield for lower mag images of coarser diatoms, but I prefer the more natural look of brightfield at higher resolution - and think I see more details with that. As you say - a matter of taste.

Rene,
It's a single stack, no stitching. This diatom *just* fit in the objective's field of view.

> "...is it possible to lower the brightness of the valve structure that is laying under the girdle? It might make the view of the girdle structure more dramatic!"
I don't think it's possible as the tone of anything "under" the girdle is mixed with the tone of the girdle and it's details. There's only one layer of pixels. I don't like to edit parts of diatoms separately anyway, it all gets the same treatment for levels, curves and contrast adjustment. I will edit messy backgrounds, but otherwise I like to keep it as "natural" as possible (i.e. like the view through the microscope, but enhanced).

Note: there's detail in the girdle that's not clear here (in the attached image). Here's a 512x512 pixel crop from the centre of the stacked image enlarged to 1024 by 1024 with no adjustments. I think you'll agree that the small details are clear. The inset is cut from this cropped image and enlarged another 3x, also no adjustments. I think I can *just* see rows of closely-spaced small pores in that. Can you?



That's not to say I wouldn't like the girdle details to be clearer and punchier, but for that I'd mount girdle bands separated from the frustule and photograph them that way. It's on the list to do now, to properly resolve those smallest pores...

Cheers
Beats

[Rene]

Yeah, either that or I am having an severe attack of dotteritis 
But if you'd like to send me some of this material, I'll check it in the SEM.

Where is it from? I haven't come across it in Dutch waters yet.

Best wishes, René

[Beatsy]

Yeah, either that or I am having an severe attack of dotteritis 
But if you'd like to send me some of this material, I'll check it in the SEM.

Where is it from? I haven't come across it in Dutch waters yet.

Best wishes, René

Hi Rene,

The (very small) cleaned sample is from Duxbury Reef, Bolinac Bay, CA, USA. It doesn't have much variety, but there are a few "pretty" species in it. Here's a few more I put in the test mount (for photographing, not an arrangement).



Can you send me a PM? For some reason I don't have permission to look at the member list, so I can't send one to you (though I can reply to PMs sent to me).

Cheers
Beats

[Rene]

Great stuff, Steve, hats off! pm send.

Found out that Mary Ann Tiffany wrote an article about girdle formation in Isthmia. You might want to ask her directly, as in her SEM images I don't see any kind of structure in the wall between the areolae.


Best, René

[anne]

Hi Steve,
resolution is absolutely great!!
best
anne