Darkfield ring needed

[Paul Dowrick]

Hello

I am looking for a dark-field ring to fit a BX53 with a universal condenser. The official U-UDA is way over priced.

Does anyone know of a suitable alternative?

Many thanks

Paul

[enricosavazzi]

Hello

I am looking for a dark-field ring to fit a BX53 with a universal condenser. The official U-UDA is way over priced.

Does anyone know of a suitable alternative?

Many thanks

Paul

I am fairly sure I have an extra UDA (genuine Olympus) in my boxes, but it might be difficult for me to find it because I am packing my things and will move about one month from now. I do know I already packed one, but I am sure I have two.

Just to make sure you know, the UDA can only be used with air universal condensers and objectives, not oil. There is also a limit on the maximum NA of the objective (which I don't remember, but the U-PlanApo 40x 0.85 is most likely not usable because its NA is too high).

For this and higher NA you need to use a dedicated darkfield condenser oiled to the slide (even with air objectives, because the darkfield air condenser does not have a sufficiently high NA to prevent the cone of light from directly hitting the objective front lens).

[Paul Dowrick]

That would be amazing if you have. Please do let me know when you get time. And, many thanks for the additional info. It is very much appreciated.

[Paul Dowrick]

Olympus seem to do a dry and an oil dark field condenser. U-DCW and U-DCD.

Which would you recommend.

[Saul]

...I am looking for a dark-field ring to fit a BX53 with a universal condenser. The official U-UDA is way over priced.

Does anyone know of a suitable alternative?...

https://www.ebay.com/itm/264308894870
Depends which universal condenser you own ...

[Paul Dowrick]

...I am looking for a dark-field ring to fit a BX53 with a universal condenser. The official U-UDA is way over priced.

Does anyone know of a suitable alternative?...

https://www.ebay.com/itm/264308894870
Depends which universal condenser you own ...

I have the U-UCD8-2

[Saul]

...I am looking for a dark-field ring to fit a BX53 with a universal condenser. The official U-UDA is way over priced.

Does anyone know of a suitable alternative?...

https://www.ebay.com/itm/264308894870
Depends which universal condenser you own ...

I have the U-UCD8-2

Will not fit. What rings (diameter & thickness) your condenser accepts ?

[enricosavazzi]

That would be amazing if you have. Please do let me know when you get time. And, many thanks for the additional info. It is very much appreciated.

Sorry, all my stuff is now packed away. I did see the second UDA mounted in my spare universal condensor (I use one universal condensor for air DIC, the other for oil so that I just need to swap condensors), but prefer not to disassemble it.

It will be some months before I am in a permanent house and can unpack the unmounted UDA.

[pbraub]

There is this guy on ebay selling a variety of condenser inserts in different sizes. I was contemplating of buying a set because i am also looking for an darkfield insert for the UCD8 but have never gotten around to.

https://www.ebay.com/itm/273087400339

Peter

[enricosavazzi]

There is this guy on ebay selling a variety of condenser inserts in different sizes. I was contemplating of buying a set because i am also looking for an darkfield insert for the UCD8 but have never gotten around to.

https://www.ebay.com/itm/273087400339

Peter

I bought a similar set a year ago or more, not necessarily from the same seller. The set was supposed to fit into the sleeve around the field lens on the base of the microscope (Olympus BX50) rather than in a condenser. However, at least two of the inserts are too big by a few mm, and a few others just a little too big to fit properly. The set also includes oblique darkfield and a variety of stop shapes.

Considering the relatively high price compared to what one actually gets, the lack of dimensional precision makes my set not worth the purchase. With some patience I could have achieved the same result by carefully hand-cutting a black sheet of thin cardboard.

[pbraub]

@enricosavazzi
thank you for sharing this experience. i think that accuracy is key here. I agree, the price (incl s&h and import duties) is prettey steep for what you get.