Lenses for Photographing Micro-Meteorites

[Michael Erlewine]

I’ve been hunting the very tiny micrometeorites that bombard the Earth, go combust, and arrive to Earth in tiny spheroid shapes from the heat.

Micrometeorites typically are 0.2 to 0.4 millimeters in size.It is said that the bombard all areas of Earth pretty-much equally, about 1 micrometeorite per square meter a year. This means they are everywhere near us, of collecting on flat roofs over time. The problem is to find them. LOL.

I am trying to rig up a system to photograph these little buggers, rather than work with a microscope. Either way, it requires delicate handling. As for light, I probably will use fiber-optics and not these side lights.

Are any of you folks doing this, and can you suggest a Nikon F-Mount lens that would be the right size to photography these meteorites?

I would like suggestions on lenses that might also work. I also may try using the Nikon Z7II with the 105m Macro S lens and see how close I get with that.

As for the micrometeors, here is how small they are, and an example of what they look like photographed.

The micrometeorite photo by © 2017 Jon Larsen/Jan Braly Kihle

The photo of a micrometeorite as a speck on the finger photo by Ryan Thompson.

Any suggestions appreciated.


Read More Here:
https://micro-meteorites.com/

[Birna Rørslett]

When people talk about using SEM techniques to get the photo, it is evident that a very high magnification is required. The F/Z-mount Nikkors go to 1:1 and that's not even in the ballpark of what is needed. There are specialised optics available in F/Z mount, for example Laowa 25/2.8, that can do 5X. By using reversed cine lenses for 16mm format you can get to 20-40X at the expense of using enormous length of bellows draw.

Much more compact setups using confocal infinity-corrected metallurgical objectives like Mitutoyo can do up towards 100X with increasing problems (read: huge problems). A microscope can give 1000X using oil- or glycerine-immersion objectives. Unfortunately, the limit of useful magnification going the direct optical way is limited to somewhere betwwen 1,000 and 1,500X and the image quality will be miles off what you are showing us in your stacked flower shots. There is also the depressing fact that with a microscope, using large sensors like those of FX cameras is not useful at all.

Find a friendly university with an SEM setup in your vicinity, and ask them what they can do for you.

[Hugh_3170]

Thanks for this interesting link Michael.  Good luck with this new project.

...

Read More Here:
https://micro-meteorites.com/

[MEPER]

It seems part of the fun is to see how far you can with using a traditional setup?

I was thinking about a reversed 20mm lens on a bellows. E.g. PB-6 first as standalone and then maybe including the extension bellows for extra magnification. I think close to x20 should be possible then?
x10 with "just" a PB-6......something like this setup.

If you have the nikkor 20/3.5 (52mm filter version) a BR2 reversing adapter can be used.
The setup is simple but to get a good image........is probably not so simple.

[MEPER]

The person here tries some traditional setups of different kinds:

https://www.throughthefmount.com/articles_tips_microphotography.html

A bit down the 20/3.5 is used reversed to get x12 magnification (on bellows and reversed on a 200mm lens).

Also the use of a Nikon 1 camera using the FT-1 adapter can be useful to get the x2.7 factor of the CX sensor compared to FX.

[Michael Erlewine]

The person here tries some traditional setups of different kinds:

https://www.throughthefmount.com/articles_tips_microphotography.html

A bit down the 20/3.5 is used reversed to get x12 magnification (on bellows and reversed on a 200mm lens).

Also the use of a Nikon 1 camera using the FT-1 adapter can be useful to get the x2.7 factor of the CX sensor compared to FX.

I will look into it. I need the camera to point straight down, so I can move the tiny stones with a toothpick.

[Dr Klaus Schmitt]

Michael, vibrations will be your biggest enemy, breathing, or walking on the floor etc will easily destroy your result(s). I would recommend to use studio flash and diffusors as the micro mount crystal people use (as these are similar in size), or strong LED lights with perfect light quality (Ra=98-100 rating), such as my friend build, the SUPERNOVA
https://www-stonemaster--onlineshop-de.translate.goog/beleuchten/leuchtmittel/segmentleuchte-supernova/?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp

And most likely you might also want to use fine stacking to get all details in focus using low magnification but long working distance microscope lenses such as the Mitutoyo M Plan Apo 5x - 10x ones...

Which might look like this, rotated to a vertical system...

[MEPER]

Via the link from Klaus I looked at the Forum and by "random" looking I found this link which shows that probably microscope lenses are the right tool for this kind of magnification:
https://krebsmicro-com.translate.goog/obj_bellows/?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp

[Birna Rørslett]

Be aware that the trend now definitely is swinging towards confocal systems and inifinity-corrected objectives. Ordinary microscope objectives usually need an addtional correction optical part, the eyepiece, and the latter has to be designed for photography, not for visual examination. Confocal systems use a *tube lens* which is principle can be any good lens with infinity focus and appropriate focal length (200mm is common). The Raynox DCR-150 is a cheap yet very god solution. No additional extension is necessary apart from spacing the Raynox at its designated distance.

Finite optics also require much longer added extension if they are used on their own, without the eyepiece. By contrast, the confocal infinity type leads to a much more compact system.  Just compare the two photos below showing setups for 20x magnification, one with the Macro-Nikkor 19mm f/2.8 lens (finite, no eyepiece) and the infinity Mitutoyo 20X objective. Both use the same Nikon Multiphot stand, and the focus stacking is achieved by a Stackshot rail moving the subject (not the lens+camera).

[MEPER]

It seems a relative recent usage of the setup with Z-camera on top?

What was the hammer used for in last picture?

[Birna Rørslett]

A hammer is always useful even for photographers.

Yes, I have been doing photomacrography with Z7 cameras for some years now. They serve the purpose well and as they run on A/C power, batteries are no issue during the often prolonged shooting sessions.

For magnifications above 20X, I prefer using a microscope.

[MEPER]

Is some of it commercial work?

Then it is easier to justify to get all the fun equipment?

I do it purely for fun. But I have various hammers...even a large one with rubber. It is often my first choice.......

[Michael Erlewine]

It’s the middle of the night and I had to get up and mess with equipment to see if I could get a decent photo. The answer: Not Really!

This equipment (and especially the lighting) was thrown together quickly with no attempt at correct lighting, etc. This was just a proof-of-concept middle-of-the-night (and can’t sleep) endeavor.

I tried two approaches, one using the Cambo Mini Actus (with long extension bellows) and an idea I got from B. Rørslett years ago in the classic “naturfotograf.com” archive (which still exists and is like a shrine!), putting the two Bellows 105 lenses together, with none reverse, coupled by the Nikon K3 adapter.

The other was to tack on some 18MM of extension to the new Z 105 Macro S f/2.8 lens.

Neither looks good, but the Bellows-lenses looked the best, AND this is probably good enough for now. After all, I still have not found a micrometeorite. This sample is just something about the size of a micrometeorite.

So, while I try to move forward, I am deflected by sidebars, like throwing this equipment together and about ten other things. I really should be out searching for micrometeorites. 

[Michael Erlewine]

I’m spending all my time sorting out this photographing of minute stones, what is called ‘stardust’. I think I have a solution, at least for now and for me. I’m using the same Cambo Actus Mini (tricked out) with a long extension rail and the inimitable Schneider Kreuznach Macro Varon 85mm f/4.5 lens.

I could not use my studio because there was a slight tremor from the floor for such a close-focus object. I had to carry everything to the basement where the floor is steady. And this is bad (unequal) lighting, yet I can fix that downstream easily.

Here is a photo of two tiny rocks, not a space rock I am sorry to say, but I am working on that.

I had to stick the stone on some reversed Gaffer tape so I could get the shot.

This is a ‘roughly’ stacked image, but good enough to tell me that if I set up the area and lights properly and get a good background, I could get a fairly usable photo until I can get to an electron microscope.

[beryllium10]

Michael,  I wish you luck in your search.  The trouble will not be getting hold of a micrometeorite, but finding it among much more abundant terrestrial dust.  Dust washed off your roof is your best bet.  A rare-earth magnet will pick up the metallic spherules, but you'll probably also get a lot of magnetite and industrial metallic particles. (NB - put the magnet in a plastic bag or paper envelope before running it over your dust.  If you don't, you'll never unstick the tiny grains.  I don't know if a summer holiday to Greenland is within your reach - but if so would be your best bet!  There micrometeorites fall all over the ice sheet and the influx of terrestrial dust is fairly low, so they end up quite highly concentrated in the sediment that accumulates in melt pools on the ice surface.  There are even more remarkable concentrations in various places in Antarctica, but much harder to get to!  I can't comment on the challenges of photographing them.  I do remember a meteoritics talk many years ago about slicing up individual 5-micrometer interplanetary dust particles into dozens of thin sections using a medical microtome, then imaging and analyzing the sections with various electron microscopy techniques!
Cheers and good luck - John