Phase contrast setup in Vickers M15 (not M15C)

[pippo1234]

I have recently bought a Vickers M15 part of a batch which belonged to a biological science university department. All microscopes in the batch come with 40x and 100x phase contrast objectives, which suggests those objectives are there by design rather than chance.

Yet, the condenser (see picture) seems to be the apochromatic or aplanatic one in the Vickers literature, rather than the phase contrast one (the latter has a rotating disc holding the annuli).

I am wondering how the lab used those phase contrast objectives. As you may see from the picture the condenser has a slot which suggests it could house a sliding holder for the annuli. Yet, there is no trace of such a condenser in the Vickers literature (neither https://groups.rifeforum.com/Files/Micr ... 204-65.pdf nor https://groups.rifeforum.com/Files/Micr ... ctions.pdf)

Would anybody have an idea of what I am dealing with? Is it the case that the lab had installed non-Vickers condensers or is that a phase contrast Vickers condenser I am not aware of. In the latter case, I'd like to be able to get hold of the annuli holder or get some information to diy it.

Many thanks in advance.

[MichaelG.]

The system diagram is here: https://dlib.york.ac.uk/yodl/app/image/ ... ref=search

Play with the buttons at bottom-right of the picture

MichaelG.

[dtsh]

I am not familiar with Vickers, but it looks like there is a slot in the condenser, just below the mount? If so, perhaps there is/was a slider with the annuli that one would slide in, like some of the DIC prisms in some other brands?

[pippo1234]

My reading of the system diagram (thank you Michael) makes me think that the condenser is not a Vickers one. The centring screws are much longer and I do not recognise the shape of the top lens. The side slots seem to have two grooves in the bottom lip which seems to suggest that they do take a slider. I attach pictures of the top and bottom of the condenser in case somebody can identify it.

[photomicro]

Your picture does not show us where a slider may fit, but the following picture shows the 'student' version of a phase condenser on the right, with the turret type ('research') on the left.

Such condensers took a slider that contained usually two different annuli and a bright-field position.

Remember, what condenser is found on an instrument of this vintage is not necessarily what it came with, as many parts were interchangeable.

The much later Vickers M10 series of microscopes, were very different in manufacture and working, but took the same condensers I think.

I think I may have one of these sliders in one of my drawers. The dimensions are roughly 3.5 inches by 1 inch wide, and about 4mm deep.

M15 cond.jpg (34.61 KiB) Viewed 335 times

Mike

[pippo1234]

Bingo! The 'student' phase condenser is the one! The picture attached to my first post shows the slot where the slider would fit.

If you don't mind parting with the slider I am interested in it.

Many thanks
Giulio

[photomicro]

Where are you based?

I am in the UK.

Mike

[pippo1234]

Me too.

Giulio

[MichaelG.]

.

Predictably excellent work, Mike

MichaelG

[photomicro]

Me too.

Giulio

If you want it, PM me. I will photograph it and send you the file, then we can arrange me posting it.