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Hello, I am looking to buy an Olympus U-DCW oil darkfield condenser (1.4-1.2 N.A.) in excellent condition. Please let me know if you have one to sell and what your price is. Thank you!

I know they want the earth for these but DF condensers are one of those components that is pretty universal. What I mean is that most oil DF condensers will do a good job as long as it fits.
The 1.2-1.4 specification is the N.A. spread of the cone of light leaving the condenser. Any condenser with similar specs. will work as well. In fact, unless you have an objective of 1.3 to 1.4 N.A., you don't need that upper limit. 1.15-1.3 for instance would do as well. If you don't need the high N.A. , one of the benefits of using a lower N.A. condenser is that it should have a broader field, allowing for use with lower magnification wide fields.
Many Chinese microscopes use the same dovetail as Olympus and those condensers are cheap. The Olympus condenser is tall, though. You would need to make sure that a retrofit condenser is tall enough. Some of the Chinese condensers look like straight knockoffs and may well be o.e.m. Olympus condensers, since Olympus is getting a pile of stuff made overseas.

Thank you for this info, Apochronaut. I have considered trying to fit up a different condenser — I’ve heard of people using Lomos and Zeiss Ultras on the BHS, for example — but I’d love to just get the right one and be done with it, certain that I’m getting the best darkfied I can. I previously had an Amscope and although the dry DF condenser was OK, the high NA oil DF condenser was very poor, so I’m not keen on the idea of the cheap Chinese stuff. And, complicating matters, I do have a PlanApo 100x iris objective with an NA of 1.4, and my entire goal here is to use it for darkfield. So I’m going to keep looking for the Olympus condenser, and probably pay an exorbitant price for it. Thanks for the thoughts!

Search eB.. for Olympus Darkfield Oil Condenser DCW 1.4-1.2 for BH and BX Series Microscopes

Thanks DeBult. You’re right, there is that one available, but I was hoping to pay less than $850. There’s also one in China for $350 but it has a strange homemade adapter and the pics he posted using the condenser are not confidence-inspiring. I am continuing to check EBay regularly though. Thank you!

ScienceMatters wrote: ↑

Wed Dec 30, 2020 11:47 pm

Thank you for this info, Apochronaut. I have considered trying to fit up a different condenser — I’ve heard of people using Lomos and Zeiss Ultras on the BHS, for example — but I’d love to just get the right one and be done with it, certain that I’m getting the best darkfied I can. I previously had an Amscope and although the dry DF condenser was OK, the high NA oil DF condenser was very poor, so I’m not keen on the idea of the cheap Chinese stuff. And, complicating matters, I do have a PlanApo 100x iris objective with an NA of 1.4, and my entire goal here is to use it for darkfield. So I’m going to keep looking for the Olympus condenser, and probably pay an exorbitant price for it. Thanks for the thoughts!

You are right. It helps to know you are on the right path with DF. The problem with Olympus is that it is TRENDING. You might get lucky and find one cheap but Chimpanzees might type out the Bible too, if enough of them tried.
One thing you should know about DF condensers is that the conceptualization of them is pretty dumbed down on a forum such as this one, where a popular obsession is fear of immersion oil. There should be a new forum category headlined Microelaiophobia. A section for the discussion of concerns and fears surrounding the impending use of immersion oil.
Oil immersion DF condensers are not one and the same. What you are looking for is a cardioid type. There is also a paraboloid type that is almost as good but they are not as common. If the condenser is stated to have an outside cone perimeter of 1.4 then it is likely a cardioid type. It is perfectly possible for an oil DF condenser to be an oil abbe type condenser but I can only see the point of that to be to sell a cheap substitute for a DF condenser. That may be the case with cheap Chinese DF condensers.
You will be able to buy s fairly inexpensive cardioid condenser to adapt to your Olympus.. Look for the N.A. above 1.3. Not all Chinese condensers are mediocre too. I know of a Chinese system that has 1.45 N.A. oil immersion planapo as an option. I think the oil DF condenser for that system is a good one and not too expesive. I expect to be trialling one early in the new year.

ScienceMatters - I just sent you a private message.

Tom

Apochronaut,

Ha ha. True about the chimpanzees, and the Microelaiophobia as well!

Everything good starts to trend and gets unobtainable. I used to buy excellent Japanese single malt whiskies for $60 and now those same bottles are hundreds of dollars. It’s maddening. I see that some lucky dog got this condenser on eBay for $45 a couple of months ago!

Using oil isn’t such a big deal, and I appreciate the info re. cardioid condensers. I now have an option to buy the Olympus one via Tom Jones here, but I look forward to hearing about your trial of the Chinese one that corresponds to the 1.45 NA system you mention. It’s good to have options since these are just going to keep getting rarer. Thanks.

ScienceMatters wrote: ↑

Thu Dec 31, 2020 9:50 pm

Thanks DeBult. You’re right, there is that one available, but I was hoping to pay less than $850. There’s also one in China for $350 but it has a strange homemade adapter and the pics he posted using the condenser are not confidence-inspiring. I am continuing to check EBay regularly though. Thank you!

The Chinese version is for Olympus BH called bh-dcw. But It still works well. I have a bh-dcd which is dry version. They have same structure with modern u-dcd or u-dcw.

Thanks! I did get my hands on both the dry and oil Olympus darkfield condensers and have been enjoying them very much.

ScienceMatters wrote: ↑

Thu Feb 25, 2021 10:45 pm

Thanks! I did get my hands on both the dry and oil Olympus darkfield condensers and have been enjoying them very much.

How much did you end up paying for the DF oil condenser if you don’t mind me asking. Thanks! (Looking for one/considering it for my microscope)

Ryanb wrote: ↑

Sat Dec 17, 2022 8:40 pm

ScienceMatters wrote: ↑

Thu Feb 25, 2021 10:45 pm

Thanks! I did get my hands on both the dry and oil Olympus darkfield condensers and have been enjoying them very much.

How much did you end up paying for the DF oil condenser if you don’t mind me asking. Thanks! (Looking for one/considering it for my microscope)

BH-DCW is less than $200 in the Chinese market

You need to make a BH2 dovetail...... I achieved it by cutting a cheap OEM condenser

Ryanb wrote: ↑

Sat Dec 17, 2022 8:40 pm

How much did you end up paying for the DF oil condenser if you don’t mind me asking. Thanks! (Looking for one/considering it for my microscope)

I paid $500 for it. I see there are a couple on eBay now for around that price.

$500 is a lot, if I recall correctly, a new one is $750-$800?
The Nikon, Zeiss, and Lomo ones fit BX, not sure about BH but making it work is just a matter of 3D printing a dovetail.
Basically, any oil condenser should be less than fussy to adapt. Evident prices have gone through the roof with many used stuff being sold for more than new.