UV (365nm) and visible (546nm) microscopy of a diatom

[dabateman]

Interesting. 

After my move I seemed to have messed up my 63x objective.  My 40x still seems ok.

Not sure what I did.

My scope is also quite dirty now. One day I will have to see if I can clean it and get things working again.

[JMC]

29 minutes ago, colinbm said:

Ok, it must be thin. At that magnification I am using 0.6um stacks & they seem too big ?

Yes a very thin diatom, and even better this one was mounted flat as well. Usually I need to stack, but not here.

[JMC]

A stack from a slide of Synedra robusta. Done on my modified Olympus BHB microscope, using 365nm light (Nemo torch). 100x Leitz Pl Apo NA 1.32-0.60 objective, oil immersion. Reichert Neo 1.42/1.18 dark ground condenser, oil immersion. Objective iris closed down to make a dark ground image. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 6 images stacked in Zerene. Reduced in resolution for sharing here (original image size 6808x4992). Also shown is a crop from the main image, again reduced in resolution for sharing.

[Andy Perrin]

Whoa, always exciting to see updates to this thread! That diatom looks like a machine part. 

[Andrea B.]

It does indeed! So cool to see these. Thanks, Jonathan.

 

BTW, I added the Macro tag.

[colinbm]

Fantastic Jonathan.

Do these repeating nano structures have any iridescence ?

[JMC]

Thanks All. I've not done much with UV on the microscope recently, as often I just use 450nm (quite a lot of slide mountants block the UV even 365nm), but will share things as and when I can.

 

Col, yes, you get some amazing effects with these repeating structures. With some diatoms as you move the stage up and down the holes go back and forth from light to dark (makes stacking a bit of a nightmare at times). Also I have some slides by Horace Dall which have had the samples coated in thin films of TiO2. They give some fanstastic colours as the film thicknesses of the TiO2 vary slightly across the sample.

 

If anyone's interested, I've put some images from a famous slide maker called Klaus Kemp here - https://jmcscientificconsulting.com/microscopy-diatom-arrangements-by-klaus-kemp/. Klaus did amazing diatom arrangements.

 

And there's some examples of Horace Dall's TiO2 coated slides here - https://jmcscientificconsulting.com/microscopy-horace-dall-titanium-dioxide-mounted-diatoms-new-images/

[colinbm]

Thanks Jonathan

[colinbm]

 

[JMC]

Thanks Colin.

[JMC]

An image of Amphipleura lindheimerii. Unknown slide maker. Olympus BHB microscope, 365nm light from a Zeiss HBO 50W mercury xenon lamp. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Abbe condenser closed down slightly, oil immersion (simple brightfield image). 2.5x Nikon CF PL photoeyepiece. Nikon d850 monochrome converted camera. Stack of 3 images in Zerene. Full image and a crop from the main image.

 

[colinbm]

Looking good Jonathan.

What diffuser is used here please ? 

[JMC]

Cheers Col. Good question. I'm not sure and let me explain. I've fitted a fused silica diffuser from Thorlabs (https://www.thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=6337) but off hand I can't remember which one is in there.

 

The background to the image has been cleaned up manually by me as well.

[colinbm]

Thanks Jonathan
I hadn't thought of ground silica. I have been using thin film PTFE or Whitish silicone film.

[JMC]

Not UV this time, but imaged using 450nm LED light. Auliscus sto[e]ckhardtii from a slide by WA Firth. This one was fun to image, and stacked really easily. Modified Olympus BHB microscope. 450nm LED light. 63x Leitz Pl Apo NA 1.40 objective with oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 22 images stacked in Zerene (Pmax setting). Shared at original pixel resolution.

[colinbm]

An excellent photo Jonathan, so sharp & clear.
Is this cell about to divide ?

[JMC]

Thanks Colin. No this is just the structure of that particular diatom. I see what you mean though. They also make me think of magnetic fields with iron filings.

[dabateman]

Yes reminds me of cell division or a coin.

Great image Jonathan. 

[photoni]

@JMC great photo, I tried to reverse and contrast it to put on the desktop... WOW

.

[JMC]

8 minutes ago, photoni said:

@JMC great photo, I tried to reverse and contrast it to put on the desktop... WOW

 

Thanks Photoni.

1 hour ago, dabateman said:

Yes reminds me of cell division or a coin.

Great image Jonathan. 

Cheers David.

[JMC]

Some more images taken using 365nm light on my Olympus BHB microscope. Images have been reduced to 1600 pixels along the long side for sharing.

 

Cymatopleura elliptica from Toomebridge, Ireland.

 

A Gomphomena, again from Toomebridge.

 

Arachnidiscus deficiens from Jackson's Paddock, Oamaru, New Zealand.

 

A fragment of Biddulphia pedalis from Oamaru, New Zealand.

[Andy Perrin]

Nice pics! You seem to end up in UV-A a lot now. 

[JMC]

13 minutes ago, Andy Perrin said:

Nice pics! You seem to end up in UV-A a lot now. 

Thanks Andy. Yes 365nm allows me to use standard optics and standard slides, and the camera is still quite sensitive, so low noise and less vibration. As such it offers benefits for resolution above and beyond visible light, without having the drawbacks of going to shorter wavelengths. Don't get me wrong, I still want to get a good image using 254nm light and a high NA objective, but that is more of an academic exercise really - to see if I can do it.

[colinbm]

Nice work Jonathan
Are these single or stacked images ?

 

[JMC]

9 hours ago, colinbm said:

Nice work Jonathan
Are these single or stacked images ?

 

These were all stacked in Zerene.