MicrobeHunter.com Microscopy Forum

Thanks, I will give it a shot, have you tried one? I was not sure how generally useful it might be since I had only found it mentioned in the context of the slit ultramicroscope. Did some more searching, the 1929 catalog referenced by the Molecular Expressions page on the slit ultramicroscope can be...

Nice fabrication, looks professional, and thanks for pointing out those LED stage inserts, I hadn't come across them before.

Ah, missed what you were saying about the protective film... so they are cut at 0, 45, and 90 degrees but not sure which is which?

I haven't been able to find any info on this except the attached ad from: Transactions of the American Microscopical Society, Vol. 44, No. 4 (Oct., 1925), pp. i-viii And brief mention here: Molecular Expressions Microscopy Primer: Museum of Microscopy - Bausch & Lomb Slit Ultramicroscope No. 22 The ...

MichaelG. wrote: ↑

Tue Aug 03, 2021 6:40 am

Has anyone considered using a ‘fibre optic faceplate’ as a straightener ?

Between the condenser and sample? Or somehow replacing the condenser?

tpruuden wrote: ↑

Mon Aug 02, 2021 5:51 pm

Wisely I marked the cut orientations on the protection film, that was removed...

What is the orientation of the beam relative to the original sheet in those three examples?

There is some relevant discussion at the beginning of chapter 3 of Bennett's book : The condenser diaphragm and the diffraction plate perform definite functions in the phase microscope. The performance of these functions is modified by both the specimen and the optical design of various components o...

I was under the impression that at least in microscope context FFP/BFP (and similar variations on those terms) refer specifically to the planes shown in your first case with infinity focus on the other side of the lens. So then when typical microscope systems are shown with stops at FFP/BFP then obj...

...is worth about a third of what you paid for the complete rotary stage. I guess confusing the serial number for a part number removed all doubt... Thanks for the suggestions, haven't fully cleaned/relubricated it yet but did end up keeping it after disassembling enough to determine that all the i...

Interesting colors, is the cyan background the color reflected from the dichroic mirror and the red/orange transmitted? Or the other way around?

Oh yeah, I had forgotten about that Leica article. I was thinking the ATC 2000 came before the Delta/HC systems, at least newer HC stuff seems to usually be clearly marked "HC", but not really sure. There was some discussion of the progression in this older thread: https://www.microbehunter.com/micr...

Since the Leica 1750 is apparently not a good match for the MicroStar IV I should get rid of it before I am inevitably tempted to buy an ATC 2000 out of curiosity. Anyone have an ATC 2000 and want it, free? I would be curious to see how the image looks in the correct stand.

Maybe we need to talk to these optical designers. There seem to be few books covering microscope optics at a level of detail that an optical designer working on even very basic microscopes would be familiar with. Of course reading general books about optics and understanding from first principles s...

it needs to be corrected in the Object plane. At high NA, SA can get really nasty, so nasty that the condenser doesn't actually manage to project high NA light on the slide. Makes sense, so basically SA of the uncorrected Abbe is so bad at high object plane NA that you don't really get anything res...

Yeah, crops from the same two photos, close but not exactly center and edge. Centering is a little off between two objectives and I adjusted positions to select nice clusters of cells and correct the centering in the crops. Maybe they still do the same trick, leave some heavy astigmatism in the obje...

Some darkfield shots showing the similar center performance but worse astigmatism, file names are descriptive. No real obvious lateral CA mismatch for the ATC 2000 objective in the MicroStar IV but might be hard to tell with the astigmatism. Ignore the magenta color artifacts in blown highlights, I ...

There is really only one arrangement of the lens cells that makes sense but I tried some others just in case and they were all much worse, as expected. So now pretty sure it is assembled correctly and the astigmatism is either the normal performance of the cheaper design or maybe a correction mismat...

No explanation but there is a statement similar to the Zeiss patent:

As is well known in the art it is the function of a microscope condenser to form a sharp image of an illuminated field diaphragm in the specimen plane of the microscope objective.

Have you ever heard of a condenser advertised as plan? I don't remember coming across one yet.

Projection with the condenser is a good idea, and seems like it should work in the other direction as well, projecting an image of a calibration slide for example. Will try tonight if I get a chance. Both of my bathrooms have windows. The fact that the large annulus is in focus, while the small no, ...

If you get a metallurgical objective its performance will be lower with a cover slip, at least if the NA os above 0.30. Nevertheless it may still be acceptable a little above that. Then they will not work, as most of the 20X mettallugical objectives I have seen they have a NA above 0.5. ... (When l...

hans wrote: ↑

Wed Jul 28, 2021 4:52 am

A mismatch between the 400-series heads/eyepieces.

Meant to say with not between.

Not sure about precise classification of "field aberrations". I think I was only using two different meanings of "field": identifying a particular set of conjugate planes in an approximately Köhler microscope referring to field (as opposed to pupil) coordinates when aberrations are expressed in tran...

I see now apochronaut's grumblings about CF marketing are not baseless... The Alphaphot was part of a wave of new product launches circa early 1980’s to accommodate the newest CF optical technology, which for the first time truly eliminated chromatic aberration. No further clarifications or qualific...

Got this out and messed with it some more... Those alignment holes need to be 4, do they not? I was expecting 4 holes too.. instead, now there are more! The original holes, my understanding is that are made to push the lens inside, not rotate it. But only two holes? Maybe are for rotating indeed. We...

Just curious … Does anyone know why the Blue wire is apparently soldered to two terminals of the socket ? No idea what variety of supplies and lamps share the connector so just guessing, but could be different pins are used for different voltage/current requirements. For example one pin is 8.3 A ma...

Looks like no ground connection originally, so yeah, I would just solder two pieces of wire 18 AWG or larger between the backsides of the contacts as circles in red. Not too much work up front, and also easy to go back if you change your mind about something. Zip tie the wires to the original cable ...

... (maybe via the outer circular metal shroud on the plug -- check continuity from that to metal on the lamp housing) ... Just realized this does not makes sense, obviously, since you do not have the circular plug ScienceMatters posted a photo of. Check whether any of the 4 blades connects to the ...

Since you're not sure everything works yet, if it were me I would start by soldering reasonably heavy (say minimum 18 AWG) wires directly between the contacts on backs of the jack and plug, which is an easily reversible modification. (Assuming the housing on the plug can be pulled back to access the...

"aplanatic" I think is made the same; the condenser iris remains in focus (w Bertrand lens) both closed and open, and this means that the condenser has no aperture spherical aberration. With an Abbe non aplanatic, the iris instead would get out of focus at different apertures. My understanding of a...