Nikon 1x 0.1 WD 35 AZ PlanApo (Help)

[Pau]

A few months back someone put a bunch of these 1x az apps up on eBay really cheap. Maybe some or all were defective, hence the price(?) ...

If you're referring to the ones still for sale at https://www.ebay.com/sch/i.html?_from=R ... _PrefLoc=2 at least two of them are worse scratched than mine, I don't see them cheap (mine came almost free with the good 4X)

[Pau]

This is solely a question of curiosity, since I am not familiar with these systems.

Looking at https://www.nikonmetrology.com/images/b ... 100-en.pdf , I don't see a "window" mentioned, but I do see lambda plates in the System Diagram on page 16.

Is the window just plain glass that substitutes for the lambda plate when that's not needed?

--Rik

Yes, a plain optical glass, in this case AR coated. Because the objectives are computed for such thick "cover glass" they need it to work rightly. The 4X /0.40 is absolutely horrible without it, lots of spherical aberration and lack of parfocality wen used with the AZ 100m zoom body.
The 1/4 wave plate is meant for polarized episcopic illumination (like the Zeiss Antiflex) to avoid reflections on lens surfaces. The system (sadly not mine) can work with DIC but the 1/4 wave plate would interfere with it, and therefore the need of a glass substitute
Nikon's AZ literature doesn't call it optical window but cover glass plate* and dummy glass*, I find the EO's optical window term preferable

* at the AZ100 "technical handbook", not cited at the document you linked

[Smokedaddy]

I'm sorry that your objective performs so badly after all the effort you've put in it. I suppose that the lens is bad.
I hope that at least the trip has been interesting.

Yea I was pretty bummed for sure but only from all the design and printing time involved. Due to lack of knowledge (or confidence), I still think I'm doing something wrong. I've had 'several' microscope-related failures in the last 12 months that still are not resolved. Those have been more of a burden than this episode by far. At least I know what a tube lens is now.

BTW, thanks for your help.
-JW:

[Scarodactyl]

I don't see them cheap (mine came almost free with the good 4X)

They weren't cheap for long. I think the initial price was like 250 and they all got scooped in a couple hours.

[Smokedaddy]

I figured I'd post a photo of another adapter I made for different-sized tube lenses. Seems very stable to me. Who know it may inspire others that own a 3D printer to make something similar instead of buying some of the more expensive adapters. Too bad I designed it for the aluminum plate made for a M38x1.25 male thread that came with my 1x objective.

[rjlittlefield]

Yes, a plain optical glass, in this case AR coated. Because the objectives are computed for such thick "cover glass" they need it to work rightly. The 4X /0.40 is absolutely horrible without it, lots of spherical aberration and lack of parfocality wen used with the AZ 100m zoom body.

Thanks, I understand this part. The NA 0.1 would be much less sensitive to spherical aberration (which I recall goes as NA^4 for wrong cover glass thickness). The loss of parfocality would be the same in terms of mm of focus shift, though less obvious due to the larger DOF at NA 0.1 .

The 1/4 wave plate is meant for polarized episcopic illumination (like the Zeiss Antiflex) to avoid reflections on lens surfaces.

This part confuses me. The combination of a linear polarizer and a 1/4 wave plate creates a circular polarizer, which blocks reflected light. So I understand how this can cut reflections from lens surfaces when the wave plate is above the lens, on the illumination side. But in the System Diagram, I see the wave plates drawn below the lens, on the subject side. In that position they can cut surface reflections from shiny subjects, but I don't see how they would affect any reflections from lens surfaces. What am I missing here?

--Rik

[Pau]

Rik, yes, the 1/4 plate is placed at the front of the objective and it is rotatable. I'm not able to elaborate a good explanation but you have a superficial one from Zeiss at:
https://zeiss-campus.magnet.fsu.edu/art ... ected.html

Polarized reflected light microscopy (Figure 6(c)) is a technique that is suitable for examining surfaces containing structures that alter the state of polarization during the reflection process. For example, structural grains in ore samples and a number of metallic alloys and thin films can be readily examined using this method. In the optical configuration outlined in Figure 6(c), the illuminating wavefronts encounter a polarizer that is placed in the vertical illuminator before the mirror unit that directs light into the objective. The linearly polarized light waves are focused onto the specimen surface and reflected back into the objective. After leaving the objective aperture as a parallel bundle of wavefronts, the light is then projected onto a second polarizer (the analyzer) oriented at 90 degrees with respect to the polarizer. Only the depolarized wavefronts are able to pass through the analyzer to reach the tube lens. An auxiliary lambda plate can also be inserted just prior to the analyzer in the optical train to examine the sign of birefringence (changing gray to color contrast). This method is sometimes referred to as sensitive tint. In cases where objectives of very low magnification are used in reflected polarized light, a rotatable optical plate (termed an Antiflex cap) consisting of a one-quarter wavelength lambda plate is placed on the objective front lens element to block reflections from the objective itself. The Antiflex method is also particularly useful when the specimen has very low reflectivity, such as would be observed in coal samples.

This system is also used in some high magnification oil immersion applications (wich I understand even less ), for example
https://onlinelibrary.wiley.com/doi/10.1111/jmi.12785

[rjlittlefield]

Pau, thanks for the references.

I think a better explanation is provided at http://www.its.caltech.edu/~bi177/priva ... beginning, page 32, where it is written that

When objectives of a very low magnification are used, a so-called Antiflex cap (a rotatable λ/4-Platte in front of the objective) permits otherwise unavoidable reflection to be also eliminated from "dark sample" surfaces.

This explanation makes perfect sense to me. Linearly polarized light coming from above, passed through a quarter-wave plate that is rotated to the correct angle, will create circularly polarized light whose reflections from surfaces can be blocked from coming back up through the system. So, I easily see that the Antiflex cap can prevent reflections from the surface of the sample, as said by this latter explanation.

But I see no way that the Antiflex cap would prevent reflections from the objective itself, as written in the explanation that you've quoted.

Of course I can always be wrong about these things, but at the moment I'm considering the part about "block reflections from the objective itself" to be erroneous. Such reflections can be blocked by circular polarization above the objective, and I've seen objectives that appear to have such an element, slightly tilted to prevent reflections from itself, mounted at the rear aperture of an objective. But for the Antiflex, I see it as only cutting reflections from the specimen surface, so as to enable better observation of the material below the surface.

If anyone has other information, I would be interested to hear.

--Rik

[Macro_Cosmos]

If anyone has other information, I would be interested to hear.

--Rik

Epi-illumination needs such a setup, I think it is not required for transillumination.

The Olympus MPlanFl N 1.25x, PlanApo 1.25x and MPlanFl N 2.5x requires polarised light, otherwise there will be a significant central hotspot.
I can ask my Olympus contact for more information. (just asked hence the edit)


The Mitutoyo 1x has a 1/4 waveplate installed at the front.

https://www.thorlabs.com/newgrouppage9. ... up_id=9895

It includes a removable waveplate that minimizes back reflections when used with an epi-illuminated system, thus enabling an increase in contrast. Magnets in the objective housing secure the wave plate in place.

The Olympus PlFl 0.5x does not seem to feature a waveplate, it is intended for transillumination only.