MicrobeHunter.com Microscopy Forum

Hmmmmm. Never thought about that since PSFs are obtained for each channel, shift and rotation corrected in software. That applies even for the best objectives. Would be more than nice to have one "perfect lens" though:-) But I would guess, yes. If the objective were perfect, and the imaging train is...

Well, that's because it isn't public (or I'm just not aware of a public source.) I asked my Nikon rep at my lab. Another way to guess the "actual" available FN would be to look into what intermediate magnification is required for imaging on the system. This has been long 2.5x (135 format, 46mm diago...

First, the tube lens can't deliver. Second, we can't see outside of around FN20mm and the center of the FoV at the same time. The second reason is why they abandoned the UW FN26.5 oculars for the UW FN25.0 oculars.

That, is due to Nikon never claiming to have a periphery perfect image in the oculars. They used to have a perfectly corrected CFD ocular for the Biophot around 1978, but didn't sell well due to it's high cost. Going back to the CFI system, Nikon's tube lens is only PSF perfect to FN18.0mm up to the...

Well, it would depend on how strict you want it to be. If it's just for getting rid of color and spherical aberrations, both would work OK. Post processing would be a bit harder since it's difficult to discern the best focus point in green while looking at an rgb image. Another consideration would b...

These stages use cross-roller bearings, and the rails that hold them are pre-tensioned and fastened with screws. A sharp knock can break this tension and give you the slight but annoying wiggle. Just loosen the screws on the guide rail, clamp it firmly, and refasten them. This only will help if the ...

viktor j nilsson wrote: ↑

Sat Oct 24, 2020 11:49 am

rests on a 'shelf' inside the hole

Exactly. Ever seen stress lines in polarized light? The last thing you would want to subject an element in a pol train is stress. Minimum amount of "soft" adhesive holds them in place.

Those wave plates are usually a sandwitch of optical glass and mica, if not quartz. Normal protocol with objectives will work Ok, just be careful not to immerse the edges with solvents that may attack the optical bonding. And dissassembling wave plates are a big nono. You'll never get the axes right...

Nice find. That objective is for the older MD, MSD scopes. That cap has a flat glass window with a thckness of 1.5mm. For inverted observation through a petri dish, it is removed and correction collar adjusted to whatever thickness the petri dish is. For normal observation on upright microscopes as ...

Interesting kit, but only simple Epi, Interference Phase Contrast, Epi DIC and parts for the Diascopic fluorescence phase unit included. No transmitted DIC. Agreed 2.5k is overblown.

Very interesting, and awesome!
Are the objectives going to be corrected for 0.17mm coverslips or will they be just for dipping??

Cheers,
John

The horror! The horror!

Ah, Ok. I’ve found it anyway. Nikon writes different info on the front and back of the objective. The seller’s photo has it on the second photo. It’s a genuine PA Lambda 20x.

Cheers,
John

BTW, do you have the URL?
Your description of the listing having Lambda etc.. only in the listing and not on the barrel...is somewhat "concerning"

Well, I've seen the Lambda 20x in pathology slide scanners but that's a recent application, and I'd doubt it would come with a case. If there are multiple examples, I would suspect a (large) lab closure, or some kind of government surplus. In that case, the intent for procurement would likely be for...

Good catch, but I'll add in some more info. The CFI60 Plan Apo Lambda 20x wasn't used in gene sequencers as far as I know. The latest machines use discrete optics tailored to each machines specific need (i.e. WD, compensation, wavelength characteristics). The brownish barrelled variants of the CFI60...

Thanks, that makes it clearer. That's the earliest version of the S-Ke in production from 1963-65. As Pete points out, this particular version with separate knobs for coarse/fine focus doesn't suffer from nylon gear fracture that is endemic with the later models. However, from the photo the scope is...

Brilliant movie!
Jamin-Lebedev interference?

Looks like there's no image?

Elaborating on Hans's post, assuming you have a phase telescope that is of Keplarian make, there is a virtual image of the objective back focal plane (BFP) to be observed just below the eyepiece. So if you can add a reticle at that plane, that will enable you to superimpose it on the BFP image. Just...

I'm nodding my head off.

Good place to start would be the equations available at Edmund Optics. It's originally for determining the acceptable displacement between an infinite objective and it's tube lens but it also would apply in an afocal setup. https://www.edmundoptics.com/knowledge-center/application-notes/microscopy/u...

Hmmmm.... how to prove if it uses fluorite...
No idea there, maybe dissasemble it? But destroying an otherwise fine objective is... painful.

Well, if the design calls for fluorite, why doubt it?

Here's the diagram for the PlanApo 100x NA1.30 from a Japanese publication.
The hatched elements are probably fluorite.

Systematic Survey on Optical Microscope Technology in Japan, C.Nagano, 国立科学博物館技術の系統化調査報告 Vol.24 2017. March. p.373

The parfocal distance is only 33.6mm compared with the 45mm of the CF series objectives intended for your Optiphot. Did they go from 33.6mm to the JIS Standard 36mm and then to DIN 45mm or did they go straight to DIN? Well, I'm not quite sure where that number for the JIS came from since Nikon has ...

Well, it's a difficult problem there. Not techincally "lying" but it's a matter of where you place the design goals and acceptable tolerances. At the time it came out, it was probably comparable to competitors designs. But over time, it became "unacceptable" and I think it was Leitz (not sure here, ...

That's one expensive lens design...
They're using 2 fluorite elements in the first embodiment, and 3(!) in the second. If they had redesigned it in 1975 (That's when Schott came out with their first ED glass FK01), that would have made an well corrected and affordable LWD objective.

That's a Plan Apo 100x NA1.30 for the older "black" painted S series microscopes from the 60-70s. The parfocal distance is only 33.6mm compared with the 45mm of the CF series objectives intended for your Optiphot. Hence the trouble mounting it (it's impossible to raise the stage to compensate) Plus,...

>Hans Yes, nice microscope but I don't own one. Too large and cumbersome with too little fraternity:-) The Apophot has a dial which has settings for each magnification, so as long as the operator is keen to adjust it every time they change mags it works like a charm. But again it's up to the operato...

>Hans Good point. Though I listed the E series as "diffusorless" actual operation normally is favored with the diffusor in the light path in diascopic illumination. This is due to compromises in the design that doesn't allow for filament position adjustment. The filament image is too large at low NA...