Reichert Zetopan - converted to infinity optics.

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Trondarne
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Reichert Zetopan - converted to infinity optics.

#1 Post by Trondarne » Tue Nov 15, 2016 11:19 am

Here is my microscope; a Reichert Zetopan from the sixties or pehaps early seventies. These Austrian microscopes where top-notch at that times, but the optics are now quite outdated compared to e.g. modern Zeiss. Originally my microscope came supplied with quite rare "Korr" and "Apo korrek" objectives - and I still have those (10x & 20x Korr, 45x & 100x Apo Korrek).

I have here made an attempt to use Zeiss infinity-corrected Plan-Neofluars on this 160 mm, I have used a tube lens taken from a broken Zeiss Axioskop prism head and a small Nikon eyepiece korrection lens.

The original Zetopan UV Phase condenser works quite well with the two Ph 2 objectives, but the Reichert Polyphos condenser (Heine type variable darkfield - phase - Bf) even better.

The image quality is ok from 20 x up, but is not very good with 1,25x, 2,5x & 10x Plan-Neofluars. The biggest improvement I can do now is nonetheless a better LED-light-source.
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zzffnn
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Re: Reichert Zetopan - converted to infinity optics.

#2 Post by zzffnn » Tue Nov 15, 2016 12:59 pm

Welcome to the forum!

Would you please share some more information about your Polyphos condenser? There is exactly one article (at MicScape, by Ian Walker) online about the Polyphos condenser. That article still does not answer my questions clearly, however.

Please kindly comment:

1) Does the Polyphos also have movable internal mirrors, EXACTLY like Leitz Heine?

2) How many condenser top lenses of different NA are available (if there are more than one), and what is the highest NA?

3) Is it correc that the Polyphos has only two easily removable parts, the removable top lens and the bottom assembly? I am asking as some eBay listings do not have all the parts (such as a Heine missing its NA 1.4 top lens).

4) how do you like Polyphos' bright field COL at NA 1.25? Micscape author (Ian Walker) said the Polyphos does not work very well for bright field COL, but did not explain clearly as to why. Is it because the broader illumination ring produces more halos (which in turn reduce bright field contrast)? Or was something caused by his Neozet scope's field lens (or lack of)?

Thank you very much!
Last edited by zzffnn on Tue Nov 15, 2016 5:03 pm, edited 8 times in total.
Selling my Canon FD 200mm F/2.8 lens

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billben74
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Re: Reichert Zetopan - converted to infinity optics.

#3 Post by billben74 » Tue Nov 15, 2016 1:21 pm

First off, welcome to forum and that looks like a really nice scope.

Now I'm no expert (others on this forum are) but my understanding is that good quality 160mmTL objectives are just as good as modern infinity? And if you have apo 160mm TL then won't they be better even than the plan neofluars, infinity?

Like I say, I'm no expert, and am more than happy to be corrected (I call that learning, and I like learning;)

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Re: Reichert Zetopan - converted to infinity optics.

#4 Post by apochronaut » Tue Nov 15, 2016 6:51 pm

billben74 wrote:First off, welcome to forum and that looks like a really nice scope.

Now I'm no expert (others on this forum are) but my understanding is that good quality 160mmTL objectives are just as good as modern infinity? And if you have apo 160mm TL then won't they be better even than the plan neofluars, infinity?

Like I say, I'm no expert, and am more than happy to be corrected (I call that learning, and I like learning;)
well, here's what I see about that, also as a non-expert but having sifted through a lot of information, systems and objectives.
160mm as a tube length was not established because it was the most desirable length technically. It was established as a compromise based on a group of factors: existing and increasing universality, size considerations, acceptable quality potential and manufacturing practicality, amongst others. No doubt there was considerable lobbying by various manufacturers in favour of 160mm as a standard, since they had a vested interest in continuing in business and no doubt some makers went by the wayside as a result of a desire to vary from the standard.
Had the R.M.S. not settled on 160mm as their standard when they did, and a standard chosen later, when certain technical innovations had emerged ; the tube length would have been longer. There is one big advantage of a longer tube and that is, that off axis rays have a narrower angle to their focus, thus increasing light transmission and reducing optical interference. It seems that a tube length of around 200mm is a better compromise than the R.M.S. standard. Infinity systems further, increase light transmission and reduce interference.
No doubt , many mfg. have taken their 160mm( and 170mm) systems to amazing heights and for most amateurs the availability of what are now considered obsolete systems in professional circles, makes the economical acquisition of some pretty nice second hand microscope systems a reality.
The major microscope manufacturers wouldn't be lock stock and barrel into infinity corrected however, if short fixed tube systems could take them where they needed to go, which is enhanced imaging. It is irrefutable that infinity corrected optics can provide sharper, better colour corrected, higher contrast microscope images than fixed tube optics within a similar optical class, with the same coatings, glass formulas, and other attention to detail. Would a cheap infinity system made in 2016 be as good as a first class 160mm system made in 1975? Probably not but with sufficient attention to detail the cheap 2016 system might be capable of providing a better future for improvement. Few such systems exist, however.
Would a quality infinity system made in 1975 given other factors being equal, be a superior system than a quality 160mm system from 1975. Not necessarily, although the potential for upgrading might be higher. Would a quality 160mm system made in 1975 have the capability of achieving the performance level of an infinity system from 1995? Not very likely, because the engineering capabilities from the 1990's on, when 160mm systems had already been mostly abandoned, far outstrip those of the 160mm systems of the past. Things such as glass formulations, computer ray tracing, etc., have changed the picture forever and the good infinity systems generally cannot be equaled by 160mm systems.
Last edited by apochronaut on Wed Nov 16, 2016 12:13 am, edited 1 time in total.

Oktagon
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Re: Reichert Zetopan - converted to infinity optics.

#5 Post by Oktagon » Tue Nov 15, 2016 11:30 pm

I will take a rare stand and partially disagree with apochromat. all things being equal, infinity systems significantly simplify the design of objectives and make them more adaptable, as well as allow introduction of mid-path components without using corrective lenses. This was the reason for moving towards infinity optics, not as much improving the quality of primary image. Having exlusively 160mm tube optics at home, and exclusively infinity systems at work from the same manufacturer (Zeiss) I must note, that objective atributes of image quality between the objectives of the same class and NA are basically the same. That makes some difference is better, more even and uniform lighting of the newer systems (such as Axio Imager II) vs. old Universal stands, wider angle eyepieces with wider 30mm tubes, better ergonomics and wider array of enhanced imaging techniques available with new systems. The other misconception commonly found with older 160mm systems is that a large number of second-hand scopes which find their way into our hope microscopy labs have not been professionally serviced and alligned for decades. While this is not a problem with simple scopes, large advanced research stands incorporate number of beam splitters, mirrors, filters, aux prizmatic elements etc. These components may or may not be properly alligned, and the fact that they look visibly clean does not mean that they are. Most of us lack skills and equipment required t properly service and align these units, which results in reduction of their performance. In addition some Zeiss optics suffers from the dreaded element separation (decementing, delamination) issues, which are only visible when they are advanced. I'm a happy owner of perfectly servised and alligned Universal with array of high end accessories, and I can easily and equaly compare quality with best modern units.
When it comes to this particular case, I would not expect to achieve performance specifications of plan-neofluars by retrpfitting them on 160mm stand and trying to adopt alternative mounting of tube lens.
I don't think that authour would end up being happy with results.

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Re: Reichert Zetopan - converted to infinity optics.

#6 Post by apochronaut » Wed Nov 16, 2016 1:59 am

Yes, it will be tricky to get the tube lens in just the right place but I don't think impossible. Is the use of the Nikon eyepieces a purposeful adjustment, intended to compensate for the tube lens location, Trondarne?



With respect to your comments re; fixed vs. infinity, Oktagon, I guess, I have a partial disagreement with your partial disagreement.
I can see that excellent performance from first rate older optics can equal the performance of more modern optics and even some 160 or 170mm stuff could challenge some infinity stuff; those older objectives wouldn't have been great in their day, otherwise. I am limited to stuff from about 2005 as my most recent optics but do also have some really fine older optics going back as far as the 1870's, with many of the intervening years represented, from many makers. In some cases and for some uses; BF for sure, even higher N.A. objectives going back into the 19th century are ridiculously fine, when compared to similar objectives from much later but a suggestion that this carries forward in any general way, from 160mm tube length objectives to the computer age infinity objectives; that there wasn't a real revolution in objective designs at work, from AO's introduction of commercial infinity correction in the early 60's up to the stunning low dispersion optics of today, is at odds with information provided by the manufacturers themselves, even Zeiss. I don't think that they are just trying to sell new microscopes, either.
Firstly, infinity objectives are if anything , more complicated than 160mm objectives. This would be dependent on individual designs of course but the reason that both Leica and Nikon have both based their current objective designs on a 25mm diameter and in the case of Nikon at least, a 60mm parfocality, is that it allows for more glass in the objective, with which to do the job required, a job that gets more optically challenging in leaps and bounds. Show me an epi fluorescence D.I.C. image from 1980 that can match the stuff they are doing today and I will believe that isn't true. Further, the longer tube length associated with infinity designs , allows for lower power plan objectives, with real imaging capability, down below 1x.
Where the simplification in optical design, with respect to an infinity corrected system comes in, is in the optical accessories. Accessories are free from tube length rectifiers, undesirable magnification enhancement, unwanted light absorption and the aberrations caused by off axis rays, making for a much better overall system microscope, with broad capability.

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Re: Reichert Zetopan - converted to infinity optics.

#7 Post by charlie g » Wed Nov 16, 2016 4:08 am

Welcome to forum, Trodarne, and thanks for your Austria/Reichert Zetopn sharing. Such a marvelous and historied stand...I wonder why you don't keep it in a corner to collect it's petigreed components over time...hey..it's your stand to enjoy as you see fit. Pardon my dismay at this chimeric surgery of the vintage Zetopan to an infinity optic stand!

I enjoy the Zetopans 'biology student :1960's Richert/Austria Biozet trinoc stand...so I,m just enthralled with the pedigree of your Zetopan. I and we all look forward to your microscopy, Trodarne. My current freshwater/wetlands live organism microscopy has my Biozet packed away except for it's field illuminator which works well with all sorts of vintage stands.

My workhorse stand is an early 1990's Nikon Labophot with trinoc head (F-trinoc head)...as I enjoy BF, DF, dl phase contrast..you guessed it...next step 'would be' DIC microscopy. I can't imagine when I can get to this next stand, however.

Welcome to forum...congrats on your Zetopan, Trodarne. charlie guevara, finger lakes/US

Oktagon
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Re: Reichert Zetopan - converted to infinity optics.

#8 Post by Oktagon » Wed Nov 16, 2016 5:04 am

apochronaut wrote: Firstly, infinity objectives are if anything , more complicated than 160mm objectives. This would be dependent on individual designs of course but the reason that both Leica and Nikon have both based their current objective designs on a 25mm diameter and in the case of Nikon at least, a 60mm parfocality, is that it allows for more glass in the objective, with which to do the job required, a job that gets more optically challenging in leaps and bounds. Show me an epi fluorescence D.I.C. image from 1980 that can match the stuff they are doing today and I will believe that isn't true. Further, the longer tube length associated with infinity designs , allows for lower power plan objectives, with real imaging capability, down below 1x.
Where the simplification in optical design, with respect to an infinity corrected system comes in, is in the optical accessories. Accessories are free from tube length rectifiers, undesirable magnification enhancement, unwanted light absorption and the aberrations caused by off axis rays, making for a much better overall system microscope, with broad capability.


These points are valid. I think the design of inifinity objectives differs significantly from manufacturer to manufacturer. 25mm ED with 60mm parfocality is not just to be able to put more glass inside, but to standartize parfocality with low power plan objectives, like 1x and lower you mentioned, as well as to have a wider FOV optics. When it comes to DIC and epiflourescense, we are again looking at auxilliary components playing principle role in image enhancement. In case of DIC, modern DIC prizms are just better alligned. Take a prime condition Zeiss DIC setup from the mid-70s and the quality of the image is going to be compatilble to todat's. As far as epiflourescence, a large portion of microscopy I do at work happens to be epiflourescent. Modern lighting and modern filters are just better. When I installed brand new filter pack into my home microscope, flourescent images became just as good as in 2014 Axio Imager. Foxed tube length is clearly a limitation, which is why major manufacturers moved away from it 25 years ago, but I stand by my original opinion that the move to infinity optics was primarily dictated by tube length condiderations rather then marked improvements in image quality.

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Re: Reichert Zetopan - converted to infinity optics.

#9 Post by Trondarne » Thu Nov 17, 2016 12:53 pm

zzffnn wrote:Welcome to the forum!

Would you please share some more information about your Polyphos condenser? There is exactly one article (at MicScape, by Ian Walker) online about the Polyphos condenser. That article still does not answer my questions clearly, however.

Please kindly comment:

1) Does the Polyphos also have movable internal mirrors, EXACTLY like Leitz Heine?

2) How many condenser top lenses of different NA are available (if there are more than one), and what is the highest NA?

3) Is it correc that the Polyphos has only two easily removable parts, the removable top lens and the bottom assembly? I am asking as some eBay listings do not have all the parts (such as a Heine missing its NA 1.4 top lens).

4) how do you like Polyphos' bright field COL at NA 1.25? Micscape author (Ian Walker) said the Polyphos does not work very well for bright field COL, but did not explain clearly as to why. Is it because the broader illumination ring produces more halos (which in turn reduce bright field contrast)? Or was something caused by his Neozet scope's field lens (or lack of)?

Thank you very much!
I cannot really answer your question since I haven't used the Heine condenser, there is neither any information on numerical aperture on the condenser itself. However, I also think the condenser is not very good for Bf.

Here are some photos, there seem to be one large mirror and a small one situated on the top of the adjustable rod - with openings outwards.
The phase annulus is therefore not flat as in a ordinary Zernike condenser, but cylindrical, and the size increases as the rod moves upwards.
Attachments
ReichertPolyphosTopLens.JPG
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ReichertPolyphosSeparated.JPG
ReichertPolyphosSeparated.JPG (113.62 KiB) Viewed 4692 times
ReichertPolyphosMirrorExposed2.JPG
ReichertPolyphosMirrorExposed2.JPG (129.24 KiB) Viewed 4692 times
ReichertPolyphosMirrorFromBottom.JPG
ReichertPolyphosMirrorFromBottom.JPG (126.52 KiB) Viewed 4692 times
ReichertPolyphosFromBottom.JPG
ReichertPolyphosFromBottom.JPG (127.26 KiB) Viewed 4692 times

dolmadis
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Re: Reichert Zetopan - converted to infinity optics.

#10 Post by dolmadis » Mon Jan 08, 2018 6:19 pm

Hi,

I know that this is an old thread but it has been referred to me by a poster on another forum.

I have been gifted a Polyphos where I understand that the top lens is missing. I do not have it to hand yet. Assuming it to be an element which unscrews I am seeking information on this to see if any replacement might be possible.

I need to know please what the top element looks like, does it unscrew and what is the top lens like? A Hemispherical lens with the curved surface downwards?

A photo or two of it perhaps with some dimensions would be helpful.

Many thanks


John

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Re: Reichert Zetopan - converted to infinity optics.

#11 Post by Hobbyst46 » Mon Jan 08, 2018 7:07 pm

Trondarne:

A very nice microscope!!
Decades ago I was using for a while a similar microscope, doing epi-fluorescence. At least on my scope, the optics were somewhat inferior relative to those of a Zeiss Universal (both 160mm optics). The Zetopan was mechanically sturdy and smooth to operate, though. I support your idea of pursuing better optics for it.

If still looking for a LED light source - the LED lamp I purchased from retroDiode.com of Texas is great - so bright I must add ND filters most of the time. It appears that they can supply a LED lamp for Reichert Zetopans, although they build to order for this scope.

To Billben74 and Apochronaut and many other members of this excellent forum:

Quote "...also as a non-expert" etc.

Well, IMO you CERTAINLY ARE experts, at least on several aspects of microscopy. There are issues that are open to debate even among experts...
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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Re: Reichert Zetopan - converted to infinity optics.

#12 Post by einman » Mon Jan 08, 2018 9:25 pm

In response to Apo's comment: "I don't think that they are just trying to sell new microscopes, either."

Based on my experience with several companies that both sell and service microscopes I have to disagree. I have seen manufacturers go after, legally, individuals posting older manuals of microscopes long out of production, but readily available on E-bay etc.

Why? Copyright infringement? I would suggest to increase the rate at which the older scopes are replaced rather than repaired.

Companies selling and repairing Olympus, Zeiss, Nikon etc will tell you getting parts to repair older model (1990's and newer) scopes is next to impossible. These manufacturers have no real interest in seeing scopes last for more than 10-15 years at most. That is one reason why you see so many high quality research scopes being offered for pennies on the dollar on E-bay compared to what they cost only a decade ago, Companies find it too expensive to maintain these scopes, due to the manufacturers charging ridiculous prices for parts, as well as high service fees. So, upon encouragement from the service/sales vendor they purchase new scopes. Construction is not up to the standards of older scopes either. The incorporation of plastics was not entirely driven by the need for anti-static material as is often mentioned.


I read one Zeiss ad where it stated that with proper maintenance their scopes could last" as long as 15 years". Really?


In regards to 160 TL vs infinity I also must also agree that infinity objectives were driven primarily by the desire to build modular scopes that allow for the addition of optics etc between the objective and the eyepiece with as little adjustment or calibration as possible.

According to Nikon- "Adding optical accessories into the light path of a fixed tube length microscope increases the effective tube length to a value greater than 160 millimeters. For this reason, addition of a vertical reflected light illuminator, polarizing intermediate stage, or similar attachment can introduce spherical aberration into an otherwise perfectly-corrected optical system. "

While the manufacturer could compensate for these aberrations etc- per Nikon-"The cost of this action was often an increase in magnification and reduced light intensities in resulting images."

Nikon makes no mention of improved resolution etc at the objective level for infinity over 160 TL as a driving force.

It was for these reasons infinity systems became the norm not because of superior optics at the objective.

I have compared my Leitz 160 TL scope to more modern infinity corrected scopes ie the Nikon 50I, Olympus BX41, Zeiss axioskop and found them to be no better. As mentioned older scopes tend to have accumulated dirt and debris, which if not properly cleaned can easily give the impression the optics are inferior to a newer infinity scope.

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Re: Reichert Zetopan - converted to infinity optics.

#13 Post by apochronaut » Tue Jan 09, 2018 2:07 pm

[quote="einman"] It was for these reasons infinity systems became the norm not because of superior optics at the objective. [quote]

Probably true, and would be demonstrable, if companies had continued to produce fixed tube optics to this day but in practice it isn't because they didn't. All of the best objectives currently available are infinity corrected. No quality manufacturer is producing 160mm microscopes anymore, so the considerable optical advancements that have taken place over the past 25-30 years, since infinity correction became the norm, rather than the exception, have been applied to infinity corrected optics, not fixed tube optics. You would be hard pressed to find anyone to agree that a 30 year old Leitz objective, despite how good it was in it's day, can compete with the resolution of a currently made Leica objective in the same class. No apochromat made as a 160mm tube length objective ever claimed to achieve resolution down to 20 nm or to have complete freedom from chromatic aberration but such claims are made today. Current objectives made by any of the high end makers are achieving previously unheard of resolution and it is coming from objective lenses that are all infinity corrected.

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Re: Reichert Zetopan - converted to infinity optics.

#14 Post by einman » Wed Jan 10, 2018 12:52 am

Agreed. However, those incredible infinity objectives new, cost more individually, than my entire system or the systems of the majority of hobbyists. Which brings us back to choosing between a research grade 160 TL scope vs a comparable infinity scope. Nikon 50I list on e-bay north of $2000 and Olympus BX41's even higher. So as much as I would love to own a new infinity system, like the ones you describe, that will most likely not happen in the near future. Unless, someone puts one for bid or for sale, not recognizing its real worth. It happens as you and I know.

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Re: Reichert Zetopan - converted to infinity optics.

#15 Post by apochronaut » Wed Jan 10, 2018 2:14 am

the nice thing is that the Leica Delta optics, fully compatible with and derived from Reichert/AO infinity D.I.N. optics are compatible with the Leica HCX 25mm thread optics. this means that a lowly Diastar ,or even Microstar IV, both of which have sold for under 200.00, can be used as a platform( and a very good one to boot) for advanced Leica infinity corrected optics, if and when they become available at an acceptable price. Olympus infinity objectives can also be used but with the proviso that the magnification will be about 11% higher. Infinity correction is not a financially crippling scenario.

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Re: Reichert Zetopan - converted to infinity optics.

#16 Post by einman » Wed Jan 10, 2018 2:24 am

apochronaut wrote:the nice thing is that the Leica Delta optics, fully compatible with and derived from Reichert/AO infinity D.I.N. optics are compatible with the Leica HCX 25mm thread optics. this means that a lowly Diastar ,or even Microstar IV, both of which have sold for under 200.00, can be used as a platform( and a very good one to boot) for advanced Leica infinity corrected optics, if and when they become available at an acceptable price. Olympus infinity objectives can also be used but with the proviso that the magnification will be about 11% higher. Infinity correction is not a financially crippling scenario.
I would very much like to see one of theses set-ups if you have one. It might be worth looking into. Do you have any pics?

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Re: Reichert Zetopan - converted to infinity optics.

#17 Post by apochronaut » Wed Jan 10, 2018 12:03 pm

I can post pictures of a Diastar equipped with planfluor and planapo optics circa 2000, if you like. Both of those are in the Delta class of optics, so they still have D.I.N. threads and parfocality but the optical corrections are compatible with HCX optics, needing an M25-D.I.N. adapter for fitting. And yes, HCX optics are still at a price point , where they sit well above what most hobbyist's are willing to pay, even for the plan achromat series'. Fortunately, Reichert, planfluor ( labelled planfluor apo, when made for the Polyvar) and planapo D.I.N. objectives are still available and frequently at prices that defy logic.

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