Microscope info

[Johnmcg]

Hi please find scope photos as promised any info would be welcomed. Is is possible to fit a Barlow lens to the Vickers scope objective has no thread and measures 53mm. Both scopes very heavy. The MJ Olympus Trinocular made in Tokio seems to have extra fittings for the model but I couldn't find much info. There is no power supply but it has a bulb and it works I don't really know what the attachment at the side is for perhaps a filter of sorts. Many thanks, John.
These scopes where bought at a British Aerospace Auction

[PeteM]

You might be able to adapt a supplementary lens to the Vickers stereo microscope - a better photo of the working end could help. There are relatively affordable Chinese supplemental lenses for stereo microscopes (2x, 1/2x etc.) and you might use filter ring adapters - typically quite affordable from China - to upsize or downsize to about the diameter of the Vickers working end. From there you'd have to improvise, the Vickers not having threads per your post. A machined ring to clamp on? Duct tape as the universal solution??

The experiment is likely to cost around $40 US and introduce a bit of aberration. Someone more familiar with Vickers might know if they made a proper solution.

The attachment on the side of your Olympus scope is for an epi illuminator. It looks like all you need is a power supply for the lamp?? You could also probably fit a LED flashlight to it and get some useful info from above the stage.

[Johnmcg]

PeteM thank you for your prompt reply I will look into what you have suggested I did have more photos but 5 is the limit per post I believe.
Kind regards, John.

[MichaelG.]

Duct tape as the universal solution??

As the wise old saying goes ...

If Duct tape doesn’t fix it, you’re not using enough Duct tape !!

MichaelG.

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P.S. Have a browse through this collection
https://dlib.york.ac.uk/yodl/app/home/s ... ry=vickers

[apochronaut]

Your microscope is a Vickers M69 stereo microscope. Since you are asking about a barlow lens for it, I am assuming that you want to increase the magnification? From the pictures, I see that it already has 20X eyepieces. The M69 is has a native 1-3X objective, so with the 3X dialed up you are already at 60X . That is at the extreme limit of any reasonable expectation of acceptable resolution for that instrument. Any further pushing of the optics are doomed to be dim and fuzzy.

If you want to reduce the magnification with a fractional supplementary lens your best route would be to source some 10X oculars for it. They should show up eventually in the U.K.

[Scarodactyl]

A 2x aux lens would (in theory, assuming it is good/compatible etc) double the NA as well, wouldn't it? So your resolution per image size doesn't necessarily change, though you lose a lot of working distance.

[apochronaut]

I wouldn't count on a supplementary objective lens , necessarily raising the N.A. in any specific proportion . Finding one that has been engineered to jack the magnification and the N.A. , yet maintain the optical corrections correctly would be a challenge, outside of an o.e.m. part.

[Johnmcg]

Hi gentlemen thank you for replying. I intend using the Vickers for pcb inspection. Magnification is good at 20:1 but I want to increase working distance using a Barlow lens if this is possible or any other suggestions.
Many thanks, John.

[apochronaut]

So, you want a fractional Barlow lens. That would normally increase the working distance by the inverse of the fractional magnification. Have you contacted any former Vickers dealers to see if such was made for that microscope? Manuals and catalogues for Vickers are not all that common but everything from the factory went to the Borthwick archive at the U. of York( not York U.). Former dealers, should still have some info.
Since there are no threads on the bottom of the objective , if there was a mechanism that was used to reduce magnification and increase working distance, it may have been installed as an alternate objective. Something like .5X to 1.5X ?

Alternately, switching the eyepieces to lower magnification can alter the working distance some. Normally, eyepieces in the same series do not alter the working distance but those of another design could do so. I know Vickers used a range of eyepiece designs but I don't know how many of them were applicable to the Stereos.

Does the image stay parfocal as you increase the objective magnification?

[MichaelG.]

Your microscope is a Vickers M69 stereo microscope. […]

I didn’t find any reference to the M69 on York’s image archive ... but here’s the M66 with a reducing lens
https://dlib.york.ac.uk/yodl/app/image/ ... ref=search
... may, or may not, be encouraging.

MichaelG.