PZO DIC

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WaterGoblin
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Joined: Wed Jan 18, 2023 7:59 pm

PZO DIC

#1 Post by WaterGoblin » Mon Jan 23, 2023 8:36 am

I am currently planning to buy a PZO biolar with DIC and I have a few questions.

-First of all is it worth it for 695€?

-how do I know if an objective is compatible with it? I know that It has to be 160mm, but is every 160mm objective compatible? does it NEED to have the ¨DIC¨ label on it? Could someone recommend me some objectives to use with it?

-Will apochromatic objectives work?

Thanks.

apochronaut
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Re: PZO DIC

#2 Post by apochronaut » Mon Jan 23, 2023 1:53 pm

695 € is a good price if it is complete and works properly. However your questions about objectives makes me believe that it is not complete. There was not a DIC label on that microscope. It can be identified by the components fitted to it. Any Biolar could be turned into a DIC version with the correct components.

Why don't you post some pictures of the scope. That is the only way to determine how complete it is.
PZO Biolar microscopes are now over 40 years old, so there is always the risk of there being some de--lamination in the system. In particular there are a couple of polarizing filters in the system prone to de-lamination that need to be intact.

WaterGoblin
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Re: PZO DIC

#3 Post by WaterGoblin » Tue Jan 24, 2023 7:40 am

It´s 2 links.

Microscope + objectives + eyepieces:https://www.avito.ru/sankt-peterburg/fo ... 2325086744

DIC SET (it`s marked as "25K roubles" but the description says has prices for every part) : https://www.avito.ru/sankt-peterburg/fo ... ion=657600

Also, I was worng about the price, corrent price is 725 euro

WaterGoblin
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Re: PZO DIC

#4 Post by WaterGoblin » Tue Jan 24, 2023 8:43 am

I am trying to figure out what objectives would be compatble as I would like to replace the default objectives with PLAN or maybe PLAN APO objectives. I know they need to be 160mm but for example
How do I know if this objective is compatible https://www.ebay.es/itm/304778942427 ? I know that it fits and that It will work with regular brightfield but I have no idea if it will work with DIC.

viktor j nilsson
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Re: PZO DIC

#5 Post by viktor j nilsson » Tue Jan 24, 2023 9:17 am

To find out what mismatcehd combinatiosn are compatible, you either need to find ask someone who has tried a specific combination, or you need to take a risk and try it yourself. There really is no other way around it.

If you want a system that you know will work 100%, you need to buy a set that was designed to work together. So, for example a BH2 with Splan achromats, or a Nikon Optiphot with CFN Plan achromats. Among the finite systems, many were designed to be used with plan achromats. But most serious microscopists wants better objectives than that. So even with a system from the big 4, people still often try different mismatched components and keep trying until they find combinations that works well enough for them. The combination people end up with is often a compromise between DIC quality and image quality. That is, I might get better DIC with the plan achromats my Vanox AH DIC system was made for, but I still almost exclusively use Plan Apochromats, as the better image quality amply compensates for the somewhat poorer DIC. Some combinations just don't work at all, though, like my PlanApo 40x 0.95. So I use an Apochromat 40x 0.85 instead, which in my case is a better compromise. In some cases, people even combine objectives from different producers. In that case, the best compromize may also factor in things like parfocal distance and eyepiece corrections. As an example, I don't get good DIC with my Olympus SB 10x PlanApo, so I instead use a Leitz 170mm 10x Plan Fluorite, or a Lomo 10x Apo. Both give excellent DIC. The Leitz gives better image quality, is plan corrected and need more similar corrections in the eyepieces than the Lomo, but has a longer parfocal distance and a different image pickup point than the Lomo. So most of the time, the Lomo is a better compromise for me.

The most common fault is that the location of the objective back focal plane is too far away from that which a specific prism was originally designed for. Say, for example that the 40x Plan Achromat my system was designed for has a BFP located very near the obejective shoulder, while my 40x PlanApo has its BFP located 4 or 5 mm further inside the objective. This may be too severe a mismatch to produce good DIC.

The unique thing about the PZO system is that you can move the objective prism vertically. So in my case, you would be able to shift the prism 4 mm downward to match the location of the BFP of my PlanApo. I can't do that in my system, so I simply can't use my 40x PlanApo for DIC.

That should make it easier to find objectives that works for you with the PZo.

Then your question must be what objectives to try. In my experience, it seems as if Plan Fluorites with high but not extremely high NAs (as a 40x 0.75 or 40x 0.85) often seem work well with DIC systems designed to be used with Plan Achromats, while objectives with very high NAs for their magnification (e.g. 10x 0.50, 40x 0.95) more often fails. I guess the "extreme" designs of the latter often pushes the location of the BFP away from that of a more "relaxed" design as the Plan Achromats and modest-NA Fluorites. But there will always be surprises.

If I didn't have a DIC setup, I would gladly pick up a PZO and start experimenting with objectives. I would probably first try to stay with 45mm parfocal objectives, and first try a bunch of stuff from Leitz (both 170mm and 160mm) and Olympus, as these are close in corrections, then from Zeiss (slightly off in corrections) and then as a last resort I would try objectives with different parfocal distances such as shortie Leits, Lomo, Zeiss Jena etc. A lot of the older fluorites and apochromats can still produce really excellent images - often dramatically better than much newer plan achromat designs (except for planarity). It is very fun to try different objectives, and if they don't work, they are usually not hard to sell for about as much as you paid (if you shop wisely).

A couple of links to see some different results with mismatched components (sometimes WILDLY mismatched!):
http://www.photomacrography.net/forum/v ... hp?t=31435
https://www.photomacrography.net/forum/ ... 28#p263828

viktor j nilsson
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Re: PZO DIC

#6 Post by viktor j nilsson » Tue Jan 24, 2023 9:23 am

I saw you linked a Nikon 160mm planapo. Since Nikon is kind of an outlier in terms of corrections in the finite era, I would stay away from them in a mix&match system. If you look at this graph:

Image
From: https://www.mikroskopie-forum.de/index. ... #msg166258

You'll see that Leitz and Olympus are close, and Zeiss are not too far off but require a little more corrections, and all of them are at least tolerably close to most other finite makers that all required at least some corrections. But Nikon was unique as they required no corrections at all. The objective in the graph is an achromat, so the deviation from zero is actually probably just a sign of being poorly corrected. A CF/CFN plan apo from that ere would be an almost perfect straight line at 0. See also recent discussion at: https://www.photomacrography.net/forum/ ... 22#p286622

So you really wouldn't want to mix Nikon with the others, and this would severely limits your options when mixing and matching.

WaterGoblin
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Re: PZO DIC

#7 Post by WaterGoblin » Tue Jan 24, 2023 9:36 am

So I should get a set of NIKON PLAN CFN objectives?

WaterGoblin
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Re: PZO DIC

#8 Post by WaterGoblin » Tue Jan 24, 2023 9:39 am

The issue with PLAN CFN is that I can't find them for a normal price, every objective I see is (apart from the 100x) is 150euro+
I found some other nikon objectives for a normal price.

WaterGoblin
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Re: PZO DIC

#9 Post by WaterGoblin » Tue Jan 24, 2023 9:39 am

I was wondering if it would be a good idea to copy the same objectives this person used: https://www.microbehunter.com/microscop ... php?t=2867

viktor j nilsson
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Re: PZO DIC

#10 Post by viktor j nilsson » Tue Jan 24, 2023 9:49 am

Sure, the Nikon CFN plans would probably work just fine. But they are Plan Achromats. Good achromats, but probably not a huge difference to the PZO achromats the PZO scope comes with. Personally, I wouldn't pay very much for such a modest improvment (when you can often pay less for better fluorite and apochromat objectives).

apochronaut
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Re: PZO DIC

#11 Post by apochronaut » Tue Jan 24, 2023 3:52 pm

I would be careful before I either made thst purchase or went ahead finding alternative objectives. There seem to be a number of missing components to both the microscope and the DIC kit

The Microscope.

I do not see a power supply or illuminator housing for the microscope. PZO used a remote power supply and either a 30 watt rear entry illuminator socket or a 100 watt lamphouse.
The objectives in the microscope are standard achromats, which will not provide a wide field plan image.
The eyepieces supplied with the microscope will be restrictive in use. Possibly the 12.5 X orthoscopic would be o.k. but both the field of view and planarity will be unsuitable. For use with PZO plan achromat objectives and in the Interference Contrast system the eyepieces required are 10X SK, the W.F. eyepieces supplied for plan compensation with PZO plan objectives. There are also 8X and 16X plan compensating eyepieces.
The 1.25X PZO head has been configured to provide an 18mm f.o.v. It would be prudent to find out if that head is capable of passing a 20mm image circle without vignetting or optical distortion. PZO plan objectives and the SK 10 plan compensating eyepieces have excellent image quality and will work well but more recently made objective and eyepiece pairs producing larger fields may have the field restricted by the head. I would want to test 20mm f.n. eyepieces first before purchasing expensive objectives in the hope of getting wider fields.

The Interference Contrast kit.

I do not see the bottom polarizing unit MPI3 ZS4. It attaches to the bottom of the Slit Condenser MPI3 ZS3 , as well as Polarizing Interference Condenser.
I do not see the Polarizing Interference Condenser KPI 2. That's the one with the compensator prisms in a rotating carousel.
I do not see the SK 10X eyepieces, necessary to use the Polarizing Interference Objectives and PZO plan objectives. The SK 10X are plan compensating but otherwise a correcting type of eyepiece. I have tried other eyepieces with the PZO plan objectives but found no other that was better. That doesn't mean there aren't any but I just didn't come across any. There may even be some with a 20mm f.o.v. and the PZO head passes it with no distortion but that will take some exprrimenting.
There appears to be a complete set of Polarizing Interference objectives in the kit: 10X,20X,40X and 100X. There are 2 extra objectives but there should be 4 other BF plan or standard achromats (those in the microscope nosepiece) .The two extra objectives appear to be duplicate Polarizing Interference objectives, so you are correct in that a 4 objective set of plan objectives is required but according to the caution above, regarding the f.o.v.

I have used Lomo 45mm D.I.N. planapochromats in a PZO but only for BF and DF. They work well but require compensating eyepieces. The SK 10 produce a fair amount of lateral ca. Olympus Bi 10XW.F. comornsate well to an 18mm f.o.v.

One other caution is regarding the Polarizing Interference head. The polarizing filter in that head is a unique 1/2 moon shape filter. There have been some problems with de-lamination and all of the PZO Interference Contrast systems are at least 40 years old now and some close to 60. I would want to be sure that filter is good. I am pretty sure though that a custom replacement is available from China. There is a guy there that will do custom glass polarizing filters.

Most of the Biolar Polarizing Interference Microscope manual is dedicated to the combination that utilizes the polarizing slit condenser. It can be used with BF objectives and the unique PZO Polarizing Interference Objectives with integrated rotating prisms for different types of Interference contrast. As such the Biolar so equipped is a type of interferometer. Only when the condenser with compensators is used does the microscope conform to what has become DIC. No where are the letters DIC referred to in the 95 page manual. Differential method of Interference Contrast is used.
The designer of the system, Max Pluta was a co-inventor of differential interference contrast. Nomarski, also a Pole, patented it in the west, subsequently licensing it in each theatre of microscope production to a company. Max Pluta continued to produce his version of it in Polsnd through PZO.

WaterGoblin
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Re: PZO DIC

#12 Post by WaterGoblin » Tue Jan 24, 2023 9:49 pm

Do you think it would be better to try to find all the parts and build a PZO DIC system or buy this: https://www.olx.ua/d/uk/obyavlenie/mkro ... derIndex=0 and try to find a condenser prism for it?

apochronaut
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Re: PZO DIC

#13 Post by apochronaut » Wed Jan 25, 2023 5:10 am

It is hard to tell because I can't read anything Cyrillic. I can only try to see what the pictures show.
No doubt a Polyvar is still a happening microscope if one has the space but parts and optics availability are slowing down. DIC on a Polyvar would be potentially superior to that on a Biolar. Wider field, plan for sure and factory options for planapochromats. PZO did not make apochromats.
Again it would depend on the price. Can you detail what the Polyvar entails? It looks like it already has some planapos and the standard 10X field is 24mm. Plenty. Even 20mm is plenty. Once it gets so you have to crank your eyeballs out of their sockets to see the edge of the field, it becomes ridiculous. Hardly anyone on this forum are pathologists looking for margins, so super wide fields start to look like more horsepower in an already ridiculously overpowered car eventually.

WaterGoblin
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Joined: Wed Jan 18, 2023 7:59 pm

Re: PZO DIC

#14 Post by WaterGoblin » Wed Jan 25, 2023 9:21 am

The polyvar basically says that it's in good condition, comes like in the photo and that everything works, I'll contact the seller later to ask some questions.
Also, about the PZO DIC. 21 hours ago this was listed: https://www.avito.ru/moskva/fototehnika ... ion=662290 It is 3000 roubles more than the other PZO DIC set but it comes with the objectives. SO I could just install it on my basic amscope microscope and have a DIC AmScope which I think would be quite funny.

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