Please help me identify this Olympus OEM 60x objective

[Macro_Cosmos]

Some time ago, I purchased this weird Olympus 60x "phase contrast" objective that popped up on eBay. Seller was from Quebec. The price was very decent and I was going to use it for phase contrast. I gathered some information and I want to identify which objective it is.
The seller claimed it comes from a "RotaChrom Chromatograph", he has another objective listed, of the same claimed origin. I looked up this machine and wasn't able to find anything.

Here it is in the middle, the two other objective are those so called "Nikon OEM 20x Na 0.75 air VC" objectives, according to ebay. I was able to track down this claim by talking to someone, this claim originated from someone who was "recycling" the Illumina GAIIx genetic sequencer on behalf of the company. It definitely requires a coverslip. More on the Nikon 20x OEM in the future.


Here are some dimensions I measured. The shell is secured via a screw and the canonical front is screwed on.

Download it here: https://live.staticflickr.com/65535/505 ... dd84_o.jpg

Here's the phase ring, it is tiny compared to two similarly powerful phase objectives.


The modified objective itself is not spring loaded, the manufacturer of that machine must have removed this function because they don't need it. This caused me to stupidly destroy an expensive diatom slide. From the third image, you can see that both the 40x and 100x features a tip that recesses into the body. This 60x however is similar to the UPlanFL N 100x UIS2, the entire front portion recesses into the body, not just the tip. At least, that's what I think. If you look at the second photo, the right most couple of images, you can see a slot in the optics housing, I think this slot is used for the spring mechanism. If only the tip recesses, I think it would be in the housing and require a deeper teardown.

Here are a couple 60x phase contrast objectives:
Both of these features a spring loaded tip. The one I have is like UIS2 objectives, the entire front portion recesses. I don't think there's a UIS objective that's designed to do so.

Here's an example:

The UIS2 60x seems to be the same.

Olympus does offer a phase contrast version of it.

Could this be the one? Maybe the manufacturer simply took the housing off, removed the spring stuff and put on a generic one. If that's true, this is a UIS2 objective. However, there's another problem, I think the phase ring is far too small. Maybe the manufacturer modified the internal optics or Olympus made a batch for them?
Dimensions seem to match up with "PLAPON60XOSC2", here: https://www.olympus-lifescience.com/en/ ... ve-finder/
Select 60x only, it's the last one.

Speaking about image quality, it is incredibly well corrected. Definitely apochromatic. I'll get some resolution chart images up later.

However, knowing nothing about the potential candidates, I can't tell for sure. If anyone has an Oly 60x NA1.42 PlanApo N, I'd like to have some rough measurements. Especially the front, my measurements are pretty rough there, a bit reluctant to just jam my callipers into it. Any help is welcomed! Thanks.

[Scarodactyl]

Oh cool! I made a thread about this listing when I first spotted it on eBay but buying it wasn't an option, so i'm really glad you're having a go at it.
I woukd bet they didn't do much modding themselves, and that most of it is custom work by olympus to spec. Hopefully that doesn't mean the phase ring is proproetary, though for this cool an objective perhaps a custom solution would be possible in that case.

[Macro_Cosmos]

Oh cool! I made a thread about this listing when I first spotted it on eBay but buying it wasn't an option, so i'm really glad you're having a go at it.
I woukd bet they didn't do much modding themselves, and that most of it is custom work by olympus to spec. Hopefully that doesn't mean the phase ring is proproetary, though for this cool an objective perhaps a custom solution would be possible in that case.

Agreed, I don't see traces of tamper with the retaining rings etc. I just need a photo of the phase contrast annulus of a 60x PlanApo N... I'm guessing it is going to be impossible to get. Phase contrast apos are extremely rare already due to very low demand. That ring is just way too small. The ring's diameter should be calculable based on some variables as they are expected to overlay the condenser's annulus perfectly, done via a centring telescope. I should try and see which ring it overlays with, I don't think it will with any on my U-PCD condenser.

[Ichthyophthirius]

Hi,

The phase ring is very small for a 60x. So it would probably work with a smaller ring annulus like Ph2 or Ph1 or a custom size. The phase contrast might not we very useful because of the reduced resolution - definitely interesting for experiments.

Does it perform as well in brightfield as the seller claimed?

Regards, Ichty

[abednego1995]

Perhaps its only me... but that outer shell on that "olympus" objective looks suspiciously Nikon...

(Plus, you bought that for 5.7k USD??? My honest opinion, is you've been scammed. Who on the earth would wrap tin foil inside an objective to fit the outer shell?? That small screw on the case doesn't engage anything inside! I'm not an Olympus person, but have due respect for what they make. The inner objective "could" be a genuine PA60x phase, but my guess is that the original objective was cosmetically unfit for selling. BTW, why in the world would a chromatograph need an oil immersion objective???)

[Macro_Cosmos]

Perhaps its only me... but that outer shell on that "olympus" objective looks suspiciously Nikon...

(Plus, you bought that for 5.7k USD??? My honest opinion, is you've been scammed. Who on the earth would wrap tin foil inside an objective to fit the outer shell?? That small screw on the case doesn't engage anything inside! I'm not an Olympus person, but have due respect for what they make. The inner objective "could" be a genuine PA60x phase, but my guess is that the original objective was cosmetically unfit for selling. BTW, why in the world would a chromatograph need an oil immersion objective???)

Nikon objectives weigh more on average, about ~15g or so. I don't think it's a Nikon, probably a good idea to test the magnification on my Oly stuff. If it's 60, then definitely not Nikon since they use 200mm TLs, 180mm will decrease the magnification by a lot, relatively speaking. Looking at the images of 60x objectives that Nikon offers, it's all very different. The tip of this weird 60x is flat and has a matte finish, there's no white/black ring around the cone. The screw simply locked the housing in, whereas the Nikon OEM ones locks the spring.

For the price, I can assure you that I paid no where near 5.7k, haha. $5.7k is enough for a couple new ones. What happened was, I got a hold of the seller outside of ebay and bought it for a bargain price. He then set the price at that ridiculous number so ebay doesn't get suspicious. If he ended the listing after I contacted him, ebay might flag it. It's been unlisted now, saying it's "not available" rather than "it has been sold".

No idea why that chromatograph would use an oil objective or phase contrast. The seller's other objective is an air one which he claimed comes from the same machine.

Some weight measurements with my kitchen scale. The objective weighs as much as Olympus' Apos.

[abednego1995]

No, "the outer shell".
The innards are probably Olympus.
I'm suggesting you got a poorly done Frankenobjektiv.

The outer shell of your lens is probably a lathed down shell of those Nikon OEM Illumina PA20x's.

[JKT]

The surface of the inner shell looks rather neat. Have you tried to remove the tinfoil to see whether there's writing under it?

[Macro_Cosmos]

The surface of the inner shell looks rather neat. Have you tried to remove the tinfoil to see whether there's writing under it?

Nope, pretty reluctant to do so as well. It's adhesive type tin foil and really sticky, what if I pull some glue out or whatever, throwing calibration off?
The shell does closely resemble the Nikon ones, maybe it's modified by the same OEM rather than Nik/Oly themselves. I'll get some more measurements up tonight, comparing the two.