Nikon Interference Phase Contrast (IPC)

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dolmadis
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Nikon Interference Phase Contrast (IPC)

#1 Post by dolmadis » Sun Apr 24, 2022 2:33 pm

Hi all, I am looking for someone who has one of these please.

Image

I would like to have some measurements of the part below which I have missing.

Image

Image

Alternatively, would also welcome anyone's thoughts on how I could use this set up without that part but somehow substituting other phase contrast plates either salvaged or printed somehow.

Thanks, John

EVILsteve
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Re: Nikon Interference Phase Contrast (IPC)

#2 Post by EVILsteve » Sun Apr 24, 2022 4:24 pm

Here's one for sale on ebay that I think you got some pictures from
https://www.ebay.ca/itm/Nikon-Interfere ... 632-2357-0

The seller claims he used an splan objective that was a good match for the anuli. Perhaps olympus anuli could be made to work with the short barrel nikons as well.

These pictures are bit confusing. Is it just the one slider your missing or both? the picture of the box looks as complete as this one one ebay other than the caps and centering telescope.

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Re: Nikon Interference Phase Contrast (IPC)

#3 Post by EVILsteve » Sun Apr 24, 2022 4:27 pm

These don't work with the newer nikon cf objective either these need the nikon short barrel objectives. Thought I would add that in case your missing less than you though just using the wrong objectives.

PeteM
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Re: Nikon Interference Phase Contrast (IPC)

#4 Post by PeteM » Sun Apr 24, 2022 4:44 pm

John, It looks like the needed annuli are just clear cutouts. If so, seems you might be able to reverse engineer it even without finding someone with one to measure?

The slider cross-sectional dimensions will be a couple thousandths less than the rectangular opening you already have. The spacing between openings won't be critical - looks like you just need to get the detents spaced right.

It also looks like you have good enough images - sufficiently straight on - to get approximate annulus dimensions. Just print out the image enlarged, and scale it to get the annulus dimensions.

There's an eBay seller who laser cuts phase annuli out of Delrin and who lists the inner and outer dimensions of the rings. Might be something close you could easily try - or someone with a laser cutter (including that seller) willing to make up some custom ones if needed.

https://www.ebay.com/sch/i.html?_dmd=2& ... st%20rings

Good excuse to buy a 3D printer and laser cutter -- or find a friend with one? Even better, make the slider out of aluminum with bored holes to fit the annuli.

I'd be inclined to get approximate annulus dimensions from a photo, buy a few that are close off eBay, and jury rig a slider to test.
Last edited by PeteM on Sun Apr 24, 2022 4:59 pm, edited 1 time in total.

viktor j nilsson
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Re: Nikon Interference Phase Contrast (IPC)

#5 Post by viktor j nilsson » Sun Apr 24, 2022 4:57 pm

Another option is to print a bunch of concentric rings of known dimension on transparent paper and put it where it is supposed to go, then look at it with a phase telescope to see which size is right.

abednego1995
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Re: Nikon Interference Phase Contrast (IPC)

#6 Post by abednego1995 » Wed Apr 27, 2022 11:07 pm

I sometimes am perplexed why people go after the IPC attachment so hard. It isn’t a true interference method as the name implies, it’s only a fancy phase setup, and due to the wider phase annuli it isn’t nice as the normal phase kit anyway. It’s for people who need it for it’s variable phase capability, and others that want a colourful background IMHO. IF you need one truely, spend on making one with the money. Making a 4f relay with a polarizers and waveplates won’t set you back 1k USD.

Cheers,
John

dolmadis
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Re: Nikon Interference Phase Contrast (IPC)

#7 Post by dolmadis » Sun May 01, 2022 11:05 am

Thanks for the replies and suggestions. (I did not get any notifications and been out of town for a few days).

I am missing the whole slider with the mounted annuli.

I have short barrel nikon objectives.

The seller on eBay that Pete mentioned seems to have blocked buyers from UK or non US.

For experimentation I could try to get a few annuli from broken condensers and see how they match but they must surely be too big.

Following the suggestion from Pete using a scaled printed image, Ignoring the black mounting, the disk is no more than 8mm in dia. Seem more like the size of objective annuli.

As regards the principles I have been "Googling" Phase Contrast with Polarisation and found some interesting hits and may be follow up on this on a conventional set up with phase objectives.

4f relay looks too complex for me based on Google.

Best, John

TiggerScope
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Re: Nikon Interference Phase Contrast (IPC)

#8 Post by TiggerScope » Fri May 20, 2022 5:22 pm

Hi Dolmadis,

This will be my first post as a forum member. I hope it's useful.

I have an IPC set which I use on an S-Ke or an Optiphot depending on my mood. The S-Ke is for when I feel purist, the Optiphot for when I want to enjoy the view through 10x/26.5 eyepieces. This is my third IPC set, the previous two having been found to be useless with 60 years of delamination, bleaching and crystallisation in the slider annuli. They don't come up on eBay too often in good shape but sometimes word of mouth in the microscope community, clubs etc can turn something up. In the UK there are quite a few meetings involving equipment sales and exchanges.

There was a complete set in Canada last year which sold for $200 BIN a few minutes after listing, quite a bargain it seemed to me, but it turned out to be faulty and the US buyer is now trying to sell it for $1500 (to be fair, he's open about the fault).

Your plans for producing annuli won't work, as the actual inserts consist of a clear annulus in a thin polarising film, with a 1/4 wave plate laminated to it at 45 degrees. The waveplate acts as the phase retarder with the front polariser wheel changing the retardation. This is interfered with the unretarded portion to produce the colours after passing the analyser. It has no connection with classical interference like Jamin-Lebedeff or Mach-Zehnder, or with DIC, but is nevertheless a true interference technique and not merely a "fancy phase setup".

I think it would be possible to make new inserts (they are located at different depths to account for different conjugate aperture planes for each objective); you'd need laser-cut pol film, 1/4 plates and glass mounting substrate. However, "possible" doesn't mean easy or quick and I'd rather spend my time doing something else, while waiting for a good set to turn up... which is in fact what I did.

As for 45mm objective compatibility, I have no trouble using CFN Plans and CFN Planapos. The previously-mentioned seller of the $1500 set apparently can't use CFN objectives, but they work for me, sometimes with a bit of condenser adjustment to enlarge or reduce the annulus diameter to better fit the IPC ring. Those old short-mount Nikon achros, while an exact match for IPC, don't give a great image. I think Nikon were still in the learning phase of objective design. BTW my Optiphot takes a modified Heine condenser, which is one way to ensure 100% compatibility of all objectives and also gives rise to further effects when adjusted, as any Heine user will know.

Good luck with the project.
Peter

dolmadis
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Re: Nikon Interference Phase Contrast (IPC)

#9 Post by dolmadis » Sat May 21, 2022 10:48 am

Thank you Peter for a great addition to this thread and explaining what I needed to know in great detail. I am now a "watcher" for a complete good one.

I would be very interested please on a new post perhaps how with a mod the Heine can be mounted on "my" Optiphot. I am a fan.

If a new post does not asppeal then do PM/DM me.

Best, John

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Re: Nikon Interference Phase Contrast (IPC)

#10 Post by TiggerScope » Sat May 21, 2022 3:05 pm

No problem to carry on here. I started with fitting a Zeiss dovetail for my Universal/UEM (first pic), then later made an adapter from Zeiss to Nikon (second pic). Seems to work well. A slight issue is that the already fairly dim Heine, combined with a 4-5 stop reduction from the three pol filters in the IPC, does push it a bit. I really have to use a bright LED, and I'm thinking to put an LED directly into the bottom of the Heine.
Zeiss dovetail and Nikon adapter
Zeiss dovetail and Nikon adapter
20220521_153303a (Medium).jpg (92.25 KiB) Viewed 6453 times
Nikon dovetail fitted
Nikon dovetail fitted
20220521_153322a (Medium).jpg (78.35 KiB) Viewed 6453 times

dolmadis
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Re: Nikon Interference Phase Contrast (IPC)

#11 Post by dolmadis » Sun May 22, 2022 5:27 am

Hi Peter

Thanks for the information on mounting a Heine on an Optiphot.

I am travelling at the moment but I will take a good look at options when I get back.

Back to the IPC.

At the time Nikon also had an alternative conventional phase set up with a condenser with smaller annuli and DLL objectives.

As you have delved and learnt about the way the IPC works is there any mileage in using the IPC head that I have, minus the slider, to any interesting imaging effect with the conventional phase condenser and the DLL’s?

Best, John

BTW my own Heine is a modified one from a uni in Germany. The bottom tube was cut down to allow it to fit into the space under under the receiver stand. Bit fiddly but works ok.

TiggerScope
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Re: Nikon Interference Phase Contrast (IPC)

#12 Post by TiggerScope » Sun May 22, 2022 6:46 pm

If you don't want a Zeiss fitment for the Heine you could just go straight with the Nikon dovetail, of course.

I can't think of anything you can do with the IPC head minus its slider. It's putting a sandwich of two rotating polarisers and a fixed 1/4 waveplate randomly in the beam path, and I don't know what use that would be other than changing the colour of the whole field, like putting a coloured filter in the illuminator. That's nothing you can't do in Photoshop if you wanted to. Now, if you had a slider to re-purpose, e.g. one with bleached annuli, you might be able to do some fun experiments in interference modulation contrast, something I might try one day if I can be bothered (though I'm not convinced of its utility).

The reason the IPC condenser has thicker annuli than the standard phase condenser is to pass more light to help out with the at least 4 stops of attenuation caused by three layers of pol film. The condensers are functionally interchangeable.

dolmadis
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Re: Nikon Interference Phase Contrast (IPC)

#13 Post by dolmadis » Sun May 22, 2022 7:08 pm

Thanks Peter for the helpful observations.

Best Regards, John

TiggerScope
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Re: Nikon Interference Phase Contrast (IPC)

#14 Post by TiggerScope » Sun May 22, 2022 11:42 pm

You're welcome, John, I'm always happy to share what I know (or what I think I know).

Good luck in finding the bits you need.

Peter

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Re: Nikon Interference Phase Contrast (IPC)

#15 Post by zzffnn » Sun May 22, 2022 11:43 pm

John,

You can probably do schlieren microscopy with that Nikon IPC, since IPC allows access to back focal plane of suitable objectives.

I cannot help you more than that though, as I only heard about it from Dave Jackson and don’t have IPC (don’t know exactly how).

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Re: Nikon Interference Phase Contrast (IPC)

#16 Post by TiggerScope » Mon May 23, 2022 12:19 pm

Well, John hasn't got a slider so it's a bit hypothetical unless he could 3D print one or carve up some aluminium billet to fit. I did suggest playing with modulation contrast (basically, Hoffman), which is a subset of Schlieren, and probably the most useful in general microscopy.

Access to conjugate BFPs is very nice to have. Some high-end microscopes had it built in, e.g. Reichert Univars and later-model Zeiss Axiomats, but it's out of fashion now, probably in order to firm up the market for phase objectives.

Peter

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Re: Nikon Interference Phase Contrast (IPC)

#17 Post by zzffnn » Mon May 23, 2022 10:06 pm

Maybe the IPC can be used to add BFP iris to short objectives? It would be somewhat useful for me, though I won’t spend collector price to buy IPC just for that.

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Re: Nikon Interference Phase Contrast (IPC)

#18 Post by TiggerScope » Tue May 24, 2022 8:56 pm

Certainly the IPC could be modified to provide a BFP iris. The actual conjugate plane is very accessible so you could put a smallish iris in there. Alternatively have you tried an RMS threaded collar with a diaphragm insert? It does work. Although it's not in the right plane it does reduce the NA, though the edge is fuzzy. And of course the TL is altered, unless one were to modify a Zeiss DIC slider collar with correction lens.

Quick question, as a matter of interest, what would you use the reduced-NA objectives for?

The term "collector price" implies very expensive... on the contrary these can be very cheap, probably because few people know what they are or do. I mentioned one which went last year for $200, and my own like-new boxed set cost me about double that, also on eBay so plenty of competition. A couple of years ago I found a fully IPC equipped L-Ke in Japan for £324! Nice. But already sold.

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Re: Nikon Interference Phase Contrast (IPC)

#19 Post by zzffnn » Tue May 24, 2022 9:40 pm

I haven’t spent enough time in this; but have only seen IPC priced at over USD $1k. Not worth it at that price for me.

Objective BFP plane iris works very well for variable circular oblique light (by controlling glares and enhancing contrast) in my hands, which works visibly better than using condenser iris.

I know RMS iris can work,but don’t like its inconveniences (as you already mentioned).

Also matching wedge masks can be put in at BFP to implement schlieren imaging. Again nice to have, if cost is reasonable.

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Re: Nikon Interference Phase Contrast (IPC)

#20 Post by TiggerScope » Sat May 28, 2022 4:03 pm

The sale price of IPC sets varies, because they are quite rare, and the seller and the bidder may have no idea of values. I don't think there is a "usual" price. Hence what happened last year; eBay seller "X", a dealer, buys a set for $200 (possibly from a house clearance), discovers it's faulty and re-lists it at $2000, later dropped to $1500.

The IPC was an expensive add-on which sold poorly in its day. I suspect nobody actually understood what they could do with it. Maybe it's the same story as the Zeiss Jamin-Lebedeff sets or the Zeiss Axiomat; ferociously expensive, superbly engineered, costing more to make than the sale price, they were terminated with few units sold.

I'd be very interested to know how many IPC sets were sold, and also in seeing a Nikon pricelist of the 1960s/70s including the IPC and S-series microscopes and accessories... if anybody can help there it'd be great.

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Re: Nikon Interference Phase Contrast (IPC)

#21 Post by abednego1995 » Sun May 29, 2022 2:01 am

TiggerScope wrote:
Sat May 28, 2022 4:03 pm
The IPC was an expensive add-on which sold poorly in its day. I suspect nobody actually understood what they could do with it. Maybe it's the same story as the Zeiss Jamin-Lebedeff sets or the Zeiss Axiomat; ferociously expensive, superbly engineered, costing more to make than the sale price, they were terminated with few units sold.
I've also been curious about this point, but considering they sold it from 1963-1976 (perhaps longer since they sold the Apophot till around 1978), I suspect they sold more than "few" units. The price, is actually interesting. I only have Japanese price lists, but they didn't change the price from 1963 to 1976, JPY95,000 flat. Factoring in inflation, that's worth about JPY440,000 (1963-2022), and JPY160,000 (1976-2022). Not sure why they didn't hike their prices but considering that the full phase contrast kit (DLL,DM,BM) was JPY88,100, and the STR-Ke being JPY150,000 in 1963, it doesn't seem too expensive. I'd rather go with the "too complicated" theory. It's not a slap on, ready out of the box thing.

IPC_1963.jpg
IPC_1963.jpg (53.39 KiB) Viewed 6048 times

Yes, they actually advertised it using it without the Ke base!

Cheers,
John

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Re: Nikon Interference Phase Contrast (IPC)

#22 Post by blekenbleu » Sun May 29, 2022 12:04 pm

abednego1995 wrote:
Sun May 29, 2022 2:01 am
considering they sold it from 1963-1976 (perhaps longer since they sold the Apophot till around 1978)
My guess is that it took Nikon that long to sell built inventories,
being from before a time that automated processes and planned obsolescence
made just-in-time and lean manufacturing economically compelling.
A significant first batch would be needed to spread costs of setting up production,
including training skilled craftsmen.
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

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Re: Nikon Interference Phase Contrast (IPC)

#23 Post by abednego1995 » Sun May 29, 2022 1:46 pm

blekenbleu wrote:
Sun May 29, 2022 12:04 pm
My guess is that it took Nikon that long to sell built inventories,
Could be. But another factor to consider, is they had at least 3 distinct generations of the attachment. Which would suggest constant development/improvement over the years. I stated 1976 as a probable end of sale date, since they went CF that year. They didn't offer the IPC unit for the Biophot and beyond.

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Re: Nikon Interference Phase Contrast (IPC)

#24 Post by TiggerScope » Tue May 31, 2022 1:47 pm

abednego1995 wrote:
Sun May 29, 2022 2:01 am
it doesn't seem too expensive. I'd rather go with the "too complicated" theory. It's not a slap on, ready out of the box thing.
I believe you may be right. It comes down to "what does this thing actually do?"... the apparatus is obviously infinitely less complicated to manufacture than J-L so obviously nowhere near the selling price.

As for how many units were sold... I still think it was very few, if frequency of appearance on eBay is any indicator. These things come up roughly as often as J-L or Axiomats, maybe once a year or less. Again maybe it wasn't the price but the ambiguity of purpose that was a deterrent. I understand that fewer than 1000 J-L kits were sold and about 600 Axiomats. It's interesting that Axiomats, J-L and IPC always seem to be in perfect cosmetic condition when I see them, showing practically no use. Unfortunately with all of them age-related deterioration is possible.
abednego1995 wrote:
Sun May 29, 2022 1:46 pm
But another factor to consider, is they had at least 3 distinct generations of the attachment.
What three? I know of two, an early one from c.1964 with levers for the polariser and analyser, and nice engraving of "interference phase contrast" on the condenser top cover. The second I know which is obviously later, has no levers but has milled polariser and analyser wheels, and the condenser has a cheap screen-printed label stuck onto the top cover.

Yes, it's odd to see a microscope with a state of the art conjugate interference phase system illuminated by a 19th century mirror. Perhaps they should have put an oil lamp in the picture.

What is an STR-Ke microscope?

Peter

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Re: Nikon Interference Phase Contrast (IPC)

#25 Post by abednego1995 » Tue May 31, 2022 4:45 pm

_
Last edited by abednego1995 on Sun Aug 21, 2022 1:58 am, edited 2 times in total.

TiggerScope
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Re: Nikon Interference Phase Contrast (IPC)

#26 Post by TiggerScope » Tue May 31, 2022 7:27 pm

That's really interesting, thanks.

I have a type 3 bought in 1964 in Yokohama by a USN medical officer (useless as faded and crystallised, and I do mean the phase plates, not the USN medical officer) with "?" slider positions as type 4, and also a type 5 with no such problems. Maybe they changed the construction of the actual phase plates? Anyway I'm not complaining, one out of two is good and the bad one will be repurposed to Schlieren experiments.

May I ask what is this detailed document you are taking snips from?

So if an STR-Ke is an S-type, how would Nikon have written an L-Ke which is also, I think, an S-type? LTR-Ke? I have only one Nikon S, an S-Ke with separate fine and coarse focus knobs, so at least I'll have no nylon gear problems.

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Re: Nikon Interference Phase Contrast (IPC)

#27 Post by abednego1995 » Wed Jun 01, 2022 3:51 am

TiggerScope wrote:
Tue May 31, 2022 7:27 pm
I have a type 3 bought in 1964 in Yokohama by a USN medical officer (useless as faded and crystallised, and I do mean the phase plates, not the USN medical officer) with "?" slider positions as type 4, and also a type 5 with no such problems. Maybe they changed the construction of the actual phase plates? Anyway I'm not complaining, one out of two is good and the bad one will be repurposed to Schlieren experiments.
Ah, nice to have objects that have history behind it. Crystallized USN officer... that probably needs another new topic thread! I've also went through various versions of the IPC, all suffer the fading equally, but as you say, the type 5 and onward seem to fare slightly better. I've told many people that the IPC unit should be able to do Schlieren in principle, but haven't done myself yet (sheepish grin) It'd be great to see images from one setup.

The snips are from product brochures, adverts, and manuals from 1962-1976.

modelS_types_1.jpg
modelS_types_1.jpg (68.99 KiB) Viewed 5843 times
L-Ke_1.jpg
L-Ke_1.jpg (87.48 KiB) Viewed 5843 times
As you say, an LTR-Ke is "possible", but at the time when the L-Ke came out the T trinoc was obsolete. The L-Ke was only offered with the type U or F type trinocs.

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Re: Nikon Interference Phase Contrast (IPC)

#28 Post by TiggerScope » Thu Jun 02, 2022 8:02 pm

abednego1995 wrote:
Wed Jun 01, 2022 3:51 am
I've also went through various versions of the IPC, all suffer the fading equally, but as you say, the type 5 and onward seem to fare slightly better.
I'm not sure what you mean by this... do you think the Type 5 and on were differently constructed? My Type 3 and Type 5 certainly aren't equally faded; the 5 is perfect, while the 3 has little trace of phase rings in the slider; they are almost completely faded away, to be replaced by spots, crystals and fungus.
abednego1995 wrote:
Wed Jun 01, 2022 3:51 am
I've told many people that the IPC unit should be able to do Schlieren in principle, but haven't done myself yet (sheepish grin) It'd be great to see images from one setup.
I've made up Hoffman plates for Nikon 4x/0.20 and 10x/0.50, both of which have the BFP accessible above the objective optics. It's an impressive view with crystals in crossed pols. But the repurposed IPC is likely to produce different results, if the modulator is made of pol film which can be darkened or lightened with the pol wheel, and colour contrast given with the analyser wheel. It's quite exciting really. We shall see.

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Re: Nikon Interference Phase Contrast (IPC)

#29 Post by dolmadis » Wed Jun 08, 2022 12:04 pm

But the repurposed IPC is likely to produce different results, if the modulator is made of pol film which can be darkened or lightened with the pol wheel, and colour contrast given with the analyser wheel. It's quite exciting really. We shall see.
Hi Pete

I would be interested in hearing more about what you plan and how you might implement this on an IPC. Because I have no idea and want to learn !!

Thanks

John

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Re: Nikon Interference Phase Contrast (IPC)

#30 Post by TiggerScope » Wed Jun 08, 2022 4:20 pm

dolmadis wrote:
Wed Jun 08, 2022 12:04 pm
I would be interested in hearing more about what you plan and how you might implement this on an IPC. Because I have no idea and want to learn !!
By all means, when I get round to it but there are a few projects higher in priority.

You will need a slider, and you could as you suggested 3D print one. The hole in your IPC body should give you the dimensions. You'll also need holes in the slider and matching optical glass discs to take the Schlieren stops.

Peter

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