microscopy!

DoctorIt

The birders and their multi-thousand $$$ primes are small potatoes...

This past week I had some down time, so I finally got around to fabricating an adapter that allows me to mount my D70 on the front port of our Nikon TE2000 inverted microscope. For anyone who's curious, it was a fairly simple matter of buying a $20 reversing ring and machining an appropriately sized mating ring to fit the 38mm port opening, and a press-fit for the 52mm threads on the opposite side. It's good to have access to a machine shop :nod

So here's some samples with my $65,000 lens:

60x Nikkor Plan APO




100x Nikkor Plan APO (oil immersion)



At 100x in oil, the deth of field is so thin that even our nanoparticles are not completely in focus. They look much better in full-size crop of that first image.

What you're looking at is essentially a "mistake", but it makes for some nice images. Some of the particles are yellow because they have been tagged with a flourescent dye (for imaging flows with our hi-speed video camera).

Hope you enjoyed a small glimpse into the micro world. I hope to have more in the future, as we try more and different projects.

Phyxius

DoctorIt wrote:

For anyone who's curious, it was a fairly simple matter of buying a $20 reversing ring and machining an appropriately sized mating ring to fit the 38mm port opening, and a press-fit for the 52mm threads on the opposite side.

Simple....

Cool pictures.

DJ-S1

This is fluid, yeah? What's with the horizontal bands in some places?

DoctorIt

DJ-S1 wrote:

This is fluid, yeah? What's with the horizontal bands in some places?

few different fluids, hence the interfaces, yup.

the bands are polarization effects as a result of all the different screens that the light passes through. I haven't figured it out exactly, but this effect shows up more in the camera than in the eyepiece of the scope... not sure if its the camera itself, or the path the light takes to get to the lower port where the camera is mounted.

pathfinder

Moire' perhaps??

DoctorIt

pathfinder wrote:

Moire' perhaps??

True, the results may look like a moire pattern... however, that which I am imaging has no pattern. Far as I know, moire patterns only happen in digital imaging when you're imaging something like a brick wall or heavily (regularly) patterned "somthing", right?

If you look at the corners of the image you can see the usual signs of polarization. Have you ever looked at a cd jewel case under a set of crossed polarizers? You have, I know you have. Those colorful waves you see in your windscreen as viewed through your plastic helmet faceshield, that's the effect we're seeing here. There are obviouly intricate lenses in the microscope, but there's also several focusing screens and prisms that split the light into the various ports.

mmroden

Your 100x plan apo looks like it might have some spherical aberration issues, especially with a newly machined mount. If you only care about 2d, that might not be a big deal, but 3d images could be hurt by it. I'm only guessing about that from the kind of odd shapes to the out of focus areas there; a lens like that should have really, really smooth out-of-focus characteristics.

Awais Yaqub

Wow great work

DoctorIt

mmroden wrote:

Your 100x plan apo looks like it might have some spherical aberration issues, especially with a newly machined mount. If you only care about 2d, that might not be a big deal, but 3d images could be hurt by it. I'm only guessing about that from the kind of odd shapes to the out of focus areas there; a lens like that should have really, really smooth out-of-focus characteristics.

you lost me a little bit

the d70 is used purely for "fun", to capture quick 2d images. 99% of our work is done via cooled CCD camera mounted on one of the side ports. We do fluidics, so we're interested in watching tagged particles move. depth of focus is important, or rather the plane at which we are focused, but beyond that, we don't much care.

so to be clear, the mount I machined is a basic adapter to attach a bayonet mount Nikon dslr to a 38mm port (a "hole"). i don't know about aberration, but clearly, the sensor of the camera isn't dead center in the imaging port.

explain to me a little bit more what you are seeing so I can tell you if I see the same thing in the eyepiece as I do in the camera.

*also, that 100x image is stacked, for better "focus", or at least I tried. The depth of field on the 100x is about 1/2 micron, the particles are just one 1 micron - which is why they look so much better in the 60x.

Skippy

DoctorIt wrote:

The birders and their multi-thousand $$$ primes are small potatoes...
This past week I had some down time, so I finally got around to fabricating an adapter that allows me to mount my D70 on the front port of our Nikon TE2000 inverted microscope. For anyone who's curious, it was a fairly simple matter of buying a $20 reversing ring and machining an appropriately sized mating ring to fit the 38mm port opening, and a press-fit for the 52mm threads on the opposite side. It's good to have access to a machine shop
So here's some samples with my $65,000 lens:
60x Nikkor Plan APO
100x Nikkor Plan APO (oil immersion)
At 100x in oil, the deth of field is so thin that even our nanoparticles are not completely in focus. They look much better in full-size crop of that first image.
What you're looking at is essentially a "mistake", but it makes for some nice images. Some of the particles are yellow because they have been tagged with a flourescent dye (for imaging flows with our hi-speed video camera).
Hope you enjoyed a small glimpse into the micro world. I hope to have more in the future, as we try more and different projects.

So you got Lens Lust too now ??? hahahaha ........HARRY!!! You have a friend now mate

Those scopes and lens don't come cheap do they, they're a lot of fun to look through too bad ya can't take it out on a field trip ha

Interesting shots Doc ........ Skippy
.

DoctorIt

Skippy wrote:

too bad ya can't take it out on a field trip ha

Yeah, it would take a little more than Harry's beach rolly to lug this one around

BigAl

Those are really cool. I should look into hooking my cam up to the department's AFM...

In the 2nd pic you say "oil immersion" what are the particulars of the 1st?

DoctorIt

BigAl wrote:

Those are really cool. I should look into hooking my cam up to the department's AFM...

In the 2nd pic you say "oil immersion" what are the particulars of the 1st?

the 100x lens requires a drop of oil between the microscope objetive and the glass slide. its designed for the index of refraction of the oil, rather than air.

mmroden

Hi Dr.,

What I meant was, the out of focus elements in the image indicate, to me at least, that the lens might have some spherical aberration. To illustrate, I hope you don't mind that I marked on your image:


The red circles have a different kind of out of focus blur to them than the blue circles. The blue side has a kind of ringing effect off the edge of the water droplets, while the red side is kind of prismatic (more so than the blue) and less jaggedy. Also, if you look at individual droplets on the red side, they go out of focus as little stars, while on the blue side they're weighted to the lower left.

If you're doing fluid dynamics work only in the plane of focus, then this kind of aberration is probably irrelevant to your work. But, you might actually be able to use it with a little trickery. If your droplets exhibit different kind of blur patterns depending on the direction they are out of focus (ie, in front of or behind the plane of focus, looking through the lens), then you can use the blur pattern to indicate which direction your droplets have moved in z. Furthermore, you can use the dispersion of the edge to figure out how far out of range they've moved.

The reason I mentioned the mount is that one way to adjust to compensate for this kind of aberration is to move the imaging device relative to the plane of focus. If your mount places the ccd of the camera at the same distance as the ccd of your main imager, you'll probably see the same effect in your images. The other source of potential problems in terms of reproducibility (if taking advantage seems like a good idea) is that coverslips are almost never the same thickness, so you'd have to use the same coverslip (or chamber, or whatever) for your experiments, which can be a real hassle.

DoctorIt

Great info - I completely understand now (I dug out my optics text after you first posted yesterday, so that helped too ). I think one of my colleagues has already been using the "trick" you mentioned. She's trying to figure out the nature of the nanoparticles you see in the droplets, so getting them focused in many planes will be helpful.

Thanks!