MicrobeHunter.com Microscopy Forum

For gravitational waves, phase plates can be made out of galaxies. Well I'm still searching for little bits of galaxy to sputter or cut from a dielectric that give me a visible spectrum Zernike phase plate. I was hoping some of the papers would have citations back to something but I didn't find any...

This article uses Zernike zone plates, but gives materials, but this probably just for x-rays: "The substrate for each of the zone plates was a 100 nm thick silicon nitride membrane with a plating base consisting of 5 nm chromium and 12 nm gold. H" https://www.osapublishing.org/DirectPDFAccess/07663...

So I think I found something to read through tonight: https://arxiv.org/ftp/arxiv/papers/1708/1708.05151.pdf "Previous Zernike phase-plates, for transmission-electron-microscopy (TEM) have always been made out of carbon. A critical constraint on those phase-plates is their fast degradation during us...

If one puts two orthogonal quarter waveplates together So putting two quarter waveplates together matching fast to slow axis by adding a 90 degree rotation between them is called a compound waveplate. Zero-order compound quarter waveplates are made to control for frequency and temperature. Nothing ...

MichaelG. wrote: ↑

Sun Jul 11, 2021 8:11 pm

Thanks for that Saul … but I have a plan

MichaelG.

Beam reducer, run it through a metre of fiber to mix, and then shoot the results into a lens to create a collimated light source.

Or do something else I guess....

I see. Where can I buy these prism mount screws? Do you have a link to where I may get some? They normally come with the prism. This e-bay item for example. I don't know the seller. I just wanted a reference image: https://www.ebay.com/itm/Olympus-Microscope-Nomarski-DIC-Prism-50X-ULWD-/173262708023

I still don't see how I'm to power this. On ebay I see lots and lots of BH2-UMA's for sale, but none of them come with power supply nor can I find the bh2 tsg transformer that's needed to power it. Surely people have a solution to this? Here are the typical lamps and power supplies for the UMA. I d...

Here some links that give part numbers and function for BH2 metallurgical/reflectance: http://www.alanwood.net/downloads/olympus-bh2-uma-instructions.pdf http://www.alanwood.net/downloads/olympus-bhm-bh-2-brochure.pdf http://www.alanwood.net/downloads/olympus-bh2-parts-diagrams-intermediate-tubes.pd...

2,516,905 - Microscope with variable polarizing and birefringent means for producing contrast in optical images 2,700,918 - Microscope with variable means for increasing the visibility of optical images These are cool. So instead of using masks, they used rings of different polarizations and a comp...

Here's a page where someone tried the candle soot option: " I tried using a circular cover slip, applying soot from a candle and and scraping it off to give a stripe, but found this difficult to do in a controlled fashion. I then tried masking the coverslip with adhesive tape before sooting, and thi...

Edit: ancient DIY phase method; the "step" and the light attenuation annulus is made by depositing candle sooth over glass. The phase material is the sooth. https://www.micromagus.net/microscopes/phase_discn.html Yes, that's the smokey thing I remember reading. I was looking for the web page but co...

If I put a ring of film-1/4-waveplate into the Fourier conjugate plane of an objective, then that just retards the light in that polarized plane. All the other light would basically not be effected. In this case the ring will retard direct-ordinary relative to direct-extraordinary by 1/4 wave. But ...

I might have found a matching diagram here: https://www.researchgate.net/figure/Sch ... _301670651

Instead the plate of the phase objectives, the annulus retards by 1/4 with respect to the light passing outside the annulus. This is due to the refractive index of glass, that is a bit thicker at the annulus, against the refractive index of air. no birifrengence. So correct me if I'm wrong or mixin...

If you are very careful you can cut a ring from plastic phase material and sandwich it in glass. But that's what led to my question. If I put a ring of film-1/4-waveplate into the Fourier conjugate plane of an objective, then that just retards the light in that polarized plane. All the other light ...

Microscope papers on various techniques use 4F to get image and Fourier conjugate planes to manipulate. But what lens design name goes with this epi design (in orange) where two lens a distance apart get field stop and aperture stops between? The Olympus AX has AS and FS reversed from the diagram be...

Thorlabs doesn't say what the material is for the ring:

https://www.thorlabs.com/newgrouppage9. ... p_id=11083

If one puts two orthogonal quarter waveplates together, would assuming a linear additive effect be valid in making a 1/4 wave retarder regardless of the polarized state of the light? I haven't figured out what the Jones matrices would be. Need to look that up.

Any pointers to example materials used for the ring in the phase plate would be appreciated.

Look for goose neck lighting or LED ring lighting, or just use a flashlight somehow mounted to aim at the sample. The LED ring light (example pictured here) can be found and not be as expensive as the gooseneck options. More officially, an epi would be used for metallurgical microscopes. If goes abo...

Hey microb did you find this lighting device useful? Regards ross I sent a message just now to hans who said they'd test one. I don't know if it is bright enough. But might be fine for a small student scope, not sure though. A flashlight is way brighter. But I like the form factor and if I can, I'l...

For positive phase contrast, the objective has a two layer ring, Figure 3a, that dims and phase shifts. The phase shift of a quarter wave confuses me. A ¼ waveplate needs an orientation with polarized light, but phase contrast is not using polarized light. Typically it uses a single frequency, like ...

I guess they are spherical mirrors:

https://spie.org/publications/tt48_376_ ... hild?SSO=1

Mirror objectives seem ill suited to use with standard refractive condensers. Systems were sold where the condenser was a mirror image of the objective. So I had taken this unit apart last year, and I forgot about the condenser. So went through the packed parts, and yep there was a condenser and it...

MicroscopyLearning wrote: ↑

Sun Jun 27, 2021 6:31 pm

Swift SW350T

Can the condenser be removed?

Is there a phase contrast option that can be bought for the Swift SW350T?

Mirror objectives seem ill suited to use with standard refractive condensers. Systems were sold where the condenser was a mirror image of the objective. Correction on my part, I had taken the unit apart so long ago, I had forgotten about the condenser, which had screws fallen into it. But yes, this...

For an IR reflective objective, the large mirror is fine, but the smaller center mirror looks foggy. Does anyone have recommendations? This is a Thermo Spectrum objective, so I don't know what coatings if any would have been done back in the early 2000 time frame. For another project, I might mill a...

Probably the first SIGGRAPH paper on microscopy:

https://s2021.siggraph.org/presentation ... ss=sess174

you need objectives with enough working distance and a stand that can accomodate large samples. Your standard Olympus stand will not be able to do this--the stage will not go low enough. For metallurgical samples like those in an epoxy mold typically about an inch in height, or maybe a sample cut o...