Nikon Fluor objectives on a Leitz stand

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einman
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Nikon Fluor objectives on a Leitz stand

#1 Post by einman » Mon Aug 19, 2019 4:46 pm

So, Although I have a complete array of Oil immersion objectives for my Leitz there are times when I would like higher resolution without resorting to the oil objectives. For example Nikon has a Fluor 20x/0.75 160 TL CF objective that I plan on comparing to my Leitz 25X/0.60 dry Fluotar and Leitz 25X/0.75 Fluotar oil immersion.

I also plan on comparing the Nikon 40x/0.85 Fluor 160 TL dry to my Leitz 40x/0.70 Fluotar dry. I do not have a comparable 40x oil objective as they have a significantly higher na of 1.3.

I have a Nikon 40X/1.3 oil immersion that performs beautifully but again not in the same class.

Both Nikons are enroute. Assuming they pass initial inspection I will post the comparison.

I will use Leitz eyepieces. I have no intention of swapping eyepieces but the Nikon objectives are CF grade and are internally corrected. Any correction by these particular Leitz eyepieces, 10x/26 Periplans , based on my reading, is minimal if any. Feel free to correct me if I am wrong. My intent is to determine the differences, if any, and subsequent improvement in ease of use with the Leitz eyepieces.

More to come.

MichaelG.
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Re: Nikon Fluor objectives on a Leitz stand

#2 Post by MichaelG. » Mon Aug 19, 2019 5:31 pm

einman wrote:... I will use Leitz eyepieces. I have no intention of swapping eyepieces but the Nikon objectives are CF grade and are internally corrected. Any correction by these particular Leitz eyepieces, 10x/26 Periplans , based on my reading, is minimal if any. Feel free to correct me if I am wrong ...
I am in no position to correct you regarding those particular Leitz eyepieces, but I would refer you to this classic note by Peter Evennett:
https://pdfs.semanticscholar.org/8a24/a ... b9a5b1.pdf

In which he clearly states:
Having made this adapter, I learned that a Leitz Periplan x10/20 GF eyepiece, type no 519 815, made 10 years or more ago, is already fitted with a 28mm x 0.75mm thread for attaching the eyecup, and was fortunate to be able to obtain one of these. A critical check of chromatic aberration correction showed that this eyepiece was suitable not only for my Leitz Ortholux (1960s vintage) but also for my Zeiss microscopes (160mm tube-length designs).
A 'critical check' by Peter would be good enough for me !
[ noting, of course, that if yours are of later manufacture they may differ ]

MichaelG.
.

P.S ... am I right in guessing that yours are 519894 ?
Too many 'projects'

MichaelG.
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Re: Nikon Fluor objectives on a Leitz stand

#3 Post by MichaelG. » Mon Aug 19, 2019 6:25 pm

At the risk of stating the obvious [and please forgive me if I am]:

The Nikon CF objectives will need an achromatic [or better] eyepiece to do them justice.

https://micro.magnet.fsu.edu/primer/ana ... ulars.html
Tells us how to differentiate between simple and more highly compensated eyepieces:
Our recommendation is to carefully choose the objective first, then purchase an eyepiece that is designed to work in conjunction with the objective. When choosing eyepieces, it is relatively easy to differentiate between simple and more highly compensated eyepieces. Simple eyepieces such as the Ramsden and Huygenian (and their more highly corrected counterparts) will appear to have a blue ring around the edge of the eyepiece diaphragm when viewed through the microscope or held up to a light source. In contrast, more highly corrected compensating eyepieces with have a yellow-red-orange ring around the diaphragm under the same circumstances.
What is not clearly stated though, is that for a fully corrected objective ...
You need an eyepiece that shows no coloured ring at all.

MichaelG.
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einman
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Re: Nikon Fluor objectives on a Leitz stand

#4 Post by einman » Mon Aug 19, 2019 7:19 pm

Thanks for the responses. Yes they are 519894.

The point of my experiment is to determine if the NIKON Fluor objectives perform better than the Leitz objectives...using the Leitz eyepieces. Simple. I am not trying to identify a better objective/eyepiece combination. Although I do have the correct Nikon 10x/26.5 eyepieces if I wanted to go that route.

If it is a simple substitution of objectives then great. If not, I simply will not use the Nikon objectives. I am well aware of the information contained within those articles. Although the use of Leitz eyepieces with a Zeiss stand, presumably with Zeiss objectives, is somewhat of a surprise.
Last edited by einman on Mon Aug 19, 2019 7:23 pm, edited 1 time in total.

MichaelG.
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Re: Nikon Fluor objectives on a Leitz stand

#5 Post by MichaelG. » Mon Aug 19, 2019 7:22 pm

I will be very interested in the result
... Please do share.

MichaelG.
Too many 'projects'

einman
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Re: Nikon Fluor objectives on a Leitz stand

#6 Post by einman » Mon Aug 19, 2019 7:26 pm

Thanks Michael. If I have to swap eyepieces to realize an improvement then that defeats my purpose as I the nosepiece would have a mixture of Leitz and Nikon objectives. Although, should using a Nikon eyepiece prove to offer significant benefits with the Nikon Fluor objectives I could set up a separate nose piece with just the Nikon Fluor objectives and then swap the eyepieces when using that nose piece.

I have several Diaplan stands so could set one up with just the Nikon objectives and eyepiece. But again not what I am after.
Last edited by einman on Mon Aug 19, 2019 7:43 pm, edited 1 time in total.

Hobbyst46
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Re: Nikon Fluor objectives on a Leitz stand

#7 Post by Hobbyst46 » Mon Aug 19, 2019 7:32 pm

einman wrote:...Although the use of Leitz eyepieces with a Zeiss stand, presumably with Zeiss objectives, is somewhat of a surprise.
I have read about more than one case where Periplans were successfuly combined with Zeiss objectives on Zeiss stands, although these were (apparently) narrower field periplans.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

einman
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Re: Nikon Fluor objectives on a Leitz stand

#8 Post by einman » Mon Aug 19, 2019 7:38 pm

Hobbyst46 wrote:
einman wrote:...Although the use of Leitz eyepieces with a Zeiss stand, presumably with Zeiss objectives, is somewhat of a surprise.
I have read about more than one case where Periplans were successfuly combined with Zeiss objectives on Zeiss stands, although these were (apparently) narrower field periplans.
I always thought Zeiss objectives required a greater degree of correction. Could be worth examining with these eyepices as there are some good deals on Zeiss objectives at times.

Although neither the Zeiss or Nikon may be parfocal with my Leitz objectives. Lots of potential playing around as winter projects.

MicroBob
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Re: Nikon Fluor objectives on a Leitz stand

#9 Post by MicroBob » Mon Aug 19, 2019 8:05 pm

Leitz used for a long time a colour correction in the eyepieces slightly less than Zeiss (West and Jena). They were far from neutral.
If the 10x 26 eyepiece fits to the Leitz objectives of the 70s and 80s it will have this colour correction.

Bob

einman
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Re: Nikon Fluor objectives on a Leitz stand

#10 Post by einman » Mon Aug 19, 2019 8:15 pm

I knew there was some degree of color correction less then Zeiss. Although I have no idea nor read of any way of quantifying it. Hopefully, not sufficient to negate any resolution improvements from the Nikon objectives.

MicroBob
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Re: Nikon Fluor objectives on a Leitz stand

#11 Post by MicroBob » Tue Aug 20, 2019 8:29 am

Here you can find interesting information on CVD:
https://www.mikroskopie-forum.de/index. ... c=22303.30

Over the decades the manufacturers have changed their systems from time to time. The stereo microscope eyepieces were different too.
So it would be interesting to hear from you when you have tested your new combinations when they arrive, Einman.

Bob

apochronaut
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Re: Nikon Fluor objectives on a Leitz stand

#12 Post by apochronaut » Tue Aug 20, 2019 9:56 am

I went through various Leitz Periplans, while looking for something that would provide a well corrected, wide enough( 18) flat image for the binocular field scope I am in the midst of making. I tried a variety of Leitz 10X from the 37mm parfocal 170mm system, the 45mm parfocal 170mm system, and the 45mm parfocal 160mm system : 5 different ones plus a 16X. Some were GF (Großes Feld), some were O, some were M but they were all marked Periplan. They were quite variable in their degree of off axis colour correction.
I also tried one pair of Zeiss KPL glasses on eyepieces and they had poorer off axis correction than any of the Leitz eyepieces, when used with my particular group of objectives . I can't recall whether the Zeiss were over or under corrected when compared to the various Leitz incarnations, just that they were not the same. However, I did not test them with 160mm Leitz or Zeiss objectives.

MicroBob
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Re: Nikon Fluor objectives on a Leitz stand

#13 Post by MicroBob » Tue Aug 20, 2019 10:56 am

Hi Phil,
the most important difference among Leitz eyepieces is whether they have their pickup point 18mm (for 170mm tube) or 10mm (for 160mm tube).
These 8mm would really make a difference if used wrong. My Leitz eyepieces of the 160mm era work well with Zeiss West objectives. The same applies to an older Leitz eyepiece of the 170mm era in combination with an 8mm distance ring.
Here is a document from Leitz that explains this 160/170mm thing: http://www.science-info.net/docs/leitz/ ... m-Memo.pdf
The 160mm Leitz eyepieces state the field number, eg Periplan 10 x 18
In the end nothing is better than a practical test.

Bob

apochronaut
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Re: Nikon Fluor objectives on a Leitz stand

#14 Post by apochronaut » Tue Aug 20, 2019 11:43 am

The intermediate image point for the two 170mm systems is the same( 152mm from the objective shoulder) but the Periplans for those two series did not seem to have the same corrections.
Leitz, as was the case with everyone else, was continually incorporating new glass technology as well as improved analytical technology into their systems and adapting lens formulas to fit.

Even at AO, where the same infinity corrected system reigned supreme between 1961 and 1985, and the bulk of the final corrections were executed in a telan lens, they used 4 different model #'s of 10X W.F. oculars over that period.

MicroBob
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Re: Nikon Fluor objectives on a Leitz stand

#15 Post by MicroBob » Tue Aug 20, 2019 12:06 pm

I think at Leitz there was a transition period when they changed from the 170mm to the 160mm setup because they were not able to have a new system ready at once. I have two Leitz objectives, one 170mm, one 160mm that are from the outside and from the optics absolutely identical. This was the objective series with the movable ring around the barrel and a fixed knurled ring. But of cause it is to be expected that there have been changes in the long time they called their eyepieces "Periplan".

MichaelG.
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Re: Nikon Fluor objectives on a Leitz stand

#16 Post by MichaelG. » Tue Aug 20, 2019 12:22 pm

MicroBob wrote:Here you can find interesting information on CVD:
https://www.mikroskopie-forum.de/index. ... c=22303.30
Interesting indeed, Bob ... Many thanks for the link
I have never found information at this level before.

DeepL translates the explanatory text as:
Explanations :
The CVD value was determined for the wavelengths 440nm and 680nm. The measurement uncertainty is +/- 0.05%. As multiband filter for both wavelengths a bulkhead UG 5 with 3mm thickness is used. In combination with a white LED there are 2 very clear intensity peaks. The Canon 450D camera for documentation purposes was attached to the microscope using special adapters so that the chip was exactly in the intermediate image plane. The distance measurement was carried out with FITSWORK, the graphic preparation and polynomial adjustment with an own program.


... which seems comprehensible; but if you can offer any improvement, please do.

MichaelG.
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MicroBob
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Re: Nikon Fluor objectives on a Leitz stand

#17 Post by MicroBob » Tue Aug 20, 2019 1:12 pm

I would optimize the translation like this:
The CVD value was determined for the wavelengths 440nm and 680nm. The measurement uncertainty is +/- 0.05%. As multiband filter for both wavelengths a SCHOTT UG 5 with 3mm thickness is used. In combination with a white LED there are 2 very clear intensity peaks. The Canon 450D camera for documentation purposes was attached to the microscope using special adapters so that the chip was exactly in the intermediate image plane. The distance measurement was carried out with FITSWORK, the graphic preparation and polynomial adjustment with an own program.
The rest is fine for me - an amazingly good automatic translation!

Peter Höbel has posted a lot of very useful things, often delivering a proof of a common theory or deviding truth and rumours.
I have a lot of trust in his measurements. One only should not make the fault to apply the results to different facts. Just because the Zeiss Jena Apo 40:1 0,95 has a CVD like Zeiss West, this doesn't mean a Zeiss Jena 10:1 0,25 has the same.

MichaelG.
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Re: Nikon Fluor objectives on a Leitz stand

#18 Post by MichaelG. » Tue Aug 20, 2019 1:21 pm

Thank you, Bob ... much appreciated.

MichaelG.
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einman
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Re: Nikon Fluor objectives on a Leitz stand

#19 Post by einman » Tue Aug 20, 2019 5:36 pm

All very good information. I have tried the Leitz 10x/26 with an Olympus objective and found them to be acceptable combinations. This is all very interesting!

MicroBob
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Re: Nikon Fluor objectives on a Leitz stand

#20 Post by MicroBob » Tue Aug 20, 2019 8:40 pm

einman wrote:I have tried the Leitz 10x/26 with an Olympus objective and found them to be acceptable combinations.
This would be in line with Peters measurements.
When I had the choice between an ancient keyhole eyepiece with perfect correction and a more modern eyepiece with higher eye relief and wider field of view but less than perfectly fitting CVD correction I might choose the latter....

Bob

einman
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Re: Nikon Fluor objectives on a Leitz stand

#21 Post by einman » Fri Aug 23, 2019 2:49 am

So as an update I thought I would begin posting specifications of the stand, objectives, eyepieces, binocular head etc.

The objectives and eyepieces will be mounted on a Leitz Diaplan stand opted with the FSA-GW-R wide field binocular head with secondary photo port. This head uses 30 mm eyepieces only. The objectives will be mounted on a 1.0x nosepiece.

Variables:

Eyepieces
• Leitz Periplan GW 10x/26 #519894
• Nikon CFUWN 10x/26.5
Objectives
• Leitz 25X/0.60 PL Fluotar WD:0.5 mm
• Leitz 40x/0.70 Pl Fluotar WD:0.45 mm
• Leitz 40x/0.65 PL WD:0.25 mm
• Leitz Fluoresz 25X/0.75 WD:0.14mm
• Nikon Fluor 20X/0.75 WD:0.66mm
• Nikon Fluor 40x/0.85 WD:0.37 mm

I will measure FOV using a calibration slide. Overall observations will be made using a diatom test slide.

I’m throwing in the Leitz Oil immersion objective to see how well the Nikon 20x/0.75 Fluor objective compares to a Leitz oil immersion objective with the same NA and approx magnification. Theoretically the oil immersion objective has the potential for superior resolution given it would not be affected by cover glass thickness, as would the dry objective of equal NA. According to Nikon at an NA of 0.75 a 0.02 mm difference in cover glass thickness from the target 0.17mm can result in about a 36% degradation of the image for a dry objective.

Ok - More to come once the Nikon 40X Fluor objective arrives. I have already taken a quick look at the Nikon Fluor 20X to confirm I got what I paid for and it looked good - very good.

MichaelG.
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Re: Nikon Fluor objectives on a Leitz stand

#22 Post by MichaelG. » Fri Aug 23, 2019 5:48 am

I'm looking forward with eager anticipation
... This should be a vey informative test.

MichaelG.
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einman
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Re: Nikon Fluor objectives on a Leitz stand

#23 Post by einman » Fri Aug 23, 2019 8:53 pm

Well the Nikon 40X/0.85 Fluor objective came in. However, it was an inferior example I fear. Although it appeared to be like new cosmetically and was without scratches etc the image appeared washed out, significantly different than any other fluor objective I own. So I sent it back. The search for another reasonably priced example continues. I will, however, check out the Nikon 20X Fluor.

Hopefully I get some time this weekend.

MichaelG.
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Re: Nikon Fluor objectives on a Leitz stand

#24 Post by MichaelG. » Fri Aug 23, 2019 9:00 pm

That's very disappointing
... any idea what may have caused the problem ?

Are Nikon fluorites prone to such failures ?
... or [heaven forfend] could it be a fake ?

MichaelG.
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viktor j nilsson
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Re: Nikon Fluor objectives on a Leitz stand

#25 Post by viktor j nilsson » Fri Aug 23, 2019 9:42 pm

Did you try to clean it? I once had an objective that looked ok when inspected by eye, but produced an inferior, washed-out image in practice. Turned out the front lens was covered by a thin layer of dried-up immersion oil. After cleaning, it was perfect. A high-NA 40x seems like a prime candidate for getting accidentally oil-dipped.

einman
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Re: Nikon Fluor objectives on a Leitz stand

#26 Post by einman » Sat Aug 24, 2019 1:32 am

I did an initial cleaning with Zeiss lens cleaner but it did not seem to help any. I was quite disappointed. In addition, rotating the collar while viewing a slide did not seem to change the image noticeably which was another sign something was not right. Rather than attempt to investigate further I chose to send it back.

I will keep my eye out for another example. In the meanwhile I will continue with the Nikon 20X Fluor.

MicroBob
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Re: Nikon Fluor objectives on a Leitz stand

#27 Post by MicroBob » Sat Aug 24, 2019 5:44 am

If higher n.a. could bring you to use oil immersion the Leitz NPL Fluotar 50:1 1,0 is very good.
Originally intended for use without cover slip the 0,29mm working distance allow to use it with one as long as the preparation is thin.
Also interesting is the Zeiss Jena 40:1 0,95 dry Apo in the later 45mm brushed chromed version. It gives a fairly flat image and the CVD compensation is not far away from Leitz. Ideally the eyepieces should pick up the image 13mm down the tube, not 10 as with the 160mm Leitz objectives, but the compensating collar will take care of this.

Bob

einman
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Re: Nikon Fluor objectives on a Leitz stand

#28 Post by einman » Sun Aug 25, 2019 2:17 am

MicroBob wrote:If higher n.a. could bring you to use oil immersion the Leitz NPL Fluotar 50:1 1,0 is very good.
Originally intended for use without cover slip the 0,29mm working distance allow to use it with one as long as the preparation is thin.
Also interesting is the Zeiss Jena 40:1 0,95 dry Apo in the later 45mm brushed chromed version. It gives a fairly flat image and the CVD compensation is not far away from Leitz. Ideally the eyepieces should pick up the image 13mm down the tube, not 10 as with the 160mm Leitz objectives, but the compensating collar will take care of this.

Bob

Thanks Bob. I have an entire nosepiece dedicated to oil immersion with a Nikon 40X 1.3 na that performs beautifully as well as a Leitz 63x/1.3. This experiment is more to determine if the Dry Nikon Fluor objectives perform superior to the Dry Leitz Fluotars using Leitz eyepieces. I often see great prices on the Nikon Fluor objectives and given their high NA have been curious about using them on my Leitz stand.

PeteM
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Re: Nikon Fluor objectives on a Leitz stand

#29 Post by PeteM » Sun Aug 25, 2019 3:14 am

I'm wondering, based on the eyepiece correction charts Bob linked to, if Olympus high NA dry objectives might not be a better match to your widefield Leitz eyepieces? The Olympus SPlans, such as the dry 100x, sometimes go somewhat affordably and cover a large field.

My understanding with the Nikons is that only the ones marked Plan Fluor are relatively flat. The regular Fluor, which go cheaper, would likely have a lot of field curvature. At least as I understand it.

MicroBob
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Re: Nikon Fluor objectives on a Leitz stand

#30 Post by MicroBob » Sun Aug 25, 2019 6:20 am

PeteM wrote:based on the eyepiece correction charts Bob linked to
Hi Pete,
I'm sure that the measurements that are shown in these diagrams are correct. But I would be hesitant to say that they present all there is to know about the CVD of five microscope companies. Apochronaut-Phil for instance had found different CVD-corrections in Leitz eyepieces. Just to put this in perspective.

Bob

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