Oil immersion lens for reflected light!

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Anton77976
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Oil immersion lens for reflected light!

#1 Post by Anton77976 » Sat Apr 10, 2021 12:29 pm

Hello everyone! And sorry for my english!
Is the Olympus M Plan 100 HI 1.25 lens designed for metallographic microscope? Is it suitable for reflected light?
I ran into the problem of contrast drop and light re-reflection when using biological oil emersion lenses designed for transmitted light!
Do you know of other inexpensive lenses with an aperture greater than 1 for reflected light? Thank you!

LouiseScot
Posts: 1167
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Location: Scotland

Re: Oil immersion lens for reflected light!

#2 Post by LouiseScot » Mon Apr 12, 2021 12:31 am

Anton77976 wrote:
Sat Apr 10, 2021 12:29 pm
Hello everyone! And sorry for my english!
Is the Olympus M Plan 100 HI 1.25 lens designed for metallographic microscope? Is it suitable for reflected light?
I ran into the problem of contrast drop and light re-reflection when using biological oil emersion lenses designed for transmitted light!
Do you know of other inexpensive lenses with an aperture greater than 1 for reflected light? Thank you!
I think the Olympus M Plans are a rather old series of objectives and probably best avoided now. There are MSPlans like this one https://www.ebay.co.uk/itm/Olympus-MS-P ... 0010.m2109 and newer, more expensive versions with bigger apertures. I don't know what the working distances of these objectives are. Also they are infinity corrected lenses. You can't use immersion lenses for reflected light. They have only short working distances - small fractions of a millimetre and won't work properly without the immersion medium.

Louise
A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

Anton77976
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Joined: Wed Apr 07, 2021 6:04 pm

Re: Oil immersion lens for reflected light!

#3 Post by Anton77976 » Mon Apr 12, 2021 8:26 pm

Thanks Louise!
Perhaps I put it wrong, by reflected light I mean not a dark field, but lighting through an illuminator.
I already have several MSPlans and NIKON M Plan and I really like how they work, but their maximum aperture is 0.9 - 0.95.
I want more resolution and I am using biological lenses, but the result is not perfect, I get very low contrast.
I think the reason is inappropriate enlightenment of such lenses.
I understand that the Olympus M Plan 100 HI 1.25 is outdated, but I can't find any new 1.25 aperture lenses.
And I do not understand why this is happening? Am I bad at searching or is oil not used in metallography?

LouiseScot
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Location: Scotland

Re: Oil immersion lens for reflected light!

#4 Post by LouiseScot » Mon Apr 12, 2021 8:49 pm

Anton77976 wrote:
Mon Apr 12, 2021 8:26 pm
Thanks Louise!
Perhaps I put it wrong, by reflected light I mean not a dark field, but lighting through an illuminator.
I already have several MSPlans and NIKON M Plan and I really like how they work, but their maximum aperture is 0.9 - 0.95.
I want more resolution and I am using biological lenses, but the result is not perfect, I get very low contrast.
I think the reason is inappropriate enlightenment of such lenses.
I understand that the Olympus M Plan 100 HI 1.25 is outdated, but I can't find any new 1.25 aperture lenses.
And I do not understand why this is happening? Am I bad at searching or is oil not used in metallography?
Reflected light means bouncing light off a target as opposed to transmitting light through it. To the best of my knowledge there aren't any low-cost larger aperture non immersion objectives. The close working distances require an immersion medium. I believe metallurgic objectives are designed to not use a coverslip?
https://www.nikonmetrology.com/images/b ... ght-en.pdf

Louise

ps I can't see how you could use reflected light with an immersion medium which assumes transmitted light - just not possible
A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

LouiseScot
Posts: 1167
Joined: Tue Jul 07, 2020 1:51 pm
Location: Scotland

Re: Oil immersion lens for reflected light!

#5 Post by LouiseScot » Mon Apr 12, 2021 9:13 pm

Here's a Nikon CF Epi 100x/0.95 - not good enough for you?

https://www.ebay.co.uk/itm/143519358173 ... WZEALw_wcB

What illumination do you use? I've been using monochromatic blue light recently (for transmitted light imaging) which seems to increase contrast over white light.

Louise
A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

MichaelG.
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Re: Oil immersion lens for reflected light!

#6 Post by MichaelG. » Mon Apr 12, 2021 10:18 pm

LouiseScot wrote:
Mon Apr 12, 2021 8:49 pm
ps I can't see how you could use reflected light with an immersion medium which assumes transmitted light - just not possible
Not quite impossible ... they are used for Coal studies:
https://www.uj.ac.za/faculties/science/ ... raphy.aspx

MichaelG.
Too many 'projects'

LouiseScot
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Location: Scotland

Re: Oil immersion lens for reflected light!

#7 Post by LouiseScot » Mon Apr 12, 2021 10:58 pm

MichaelG. wrote:
Mon Apr 12, 2021 10:18 pm
LouiseScot wrote:
Mon Apr 12, 2021 8:49 pm
ps I can't see how you could use reflected light with an immersion medium which assumes transmitted light - just not possible
Not quite impossible ... they are used for Coal studies:
https://www.uj.ac.za/faculties/science/ ... raphy.aspx

MichaelG.
Wow - that's an eye opener! I wonder how they achieve it? The Zeiss Axio Imager 2 is pretty sophisticated - with a price tag to match! https://www.ctk-instruments.com/Zeiss_A ... ochure.pdf

Even so, the Zeiss EC Epiplan objectives don't seem to go above 0.95.

For Anton: I think the 'HI' on the 100x vintage objective mentioned above stands for 'Homogenous Immersion' i.e. matching refractive indices. So presumably that involves immersion oil. I've seen a few about on Ebay - both Nikon and Olympus versions.

Louise

ps Ah, I see now - they use illumination via the (special) objective itself and in a similar manner to fluorescence microscopes http://zeiss-campus.magnet.fsu.edu/arti ... ected.html
A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

MicroBob
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Re: Oil immersion lens for reflected light!

#8 Post by MicroBob » Tue Apr 13, 2021 6:00 am

Hi Anton,
I have a Zeiss Epiplan HD 100 /1,25 oil Epi bright/dark field objective. Illumination is by means of the Epi condenser from above, either through the objective lenses or over the ring mirror. I haven't found a use for it so far, but is for sure useful for inspection of very flat surfaces.
Generally Epi bright field is giving low contrast images because the light passes the objective lenses twice and some is scattered. Polarisation helps a lot here. Perhaps you objective is a bit dusty or moldy, this would show heavily in Epi bright field.

What setup are you using and what are you observing?

Bob

Anton77976
Posts: 6
Joined: Wed Apr 07, 2021 6:04 pm

Re: Oil immersion lens for reflected light!

#9 Post by Anton77976 » Wed Apr 14, 2021 11:16 am

MicroBob wrote:
Tue Apr 13, 2021 6:00 am
Hi Anton,
I have a Zeiss Epiplan HD 100 /1,25 oil Epi bright/dark field objective. Illumination is by means of the Epi condenser from above, either through the objective lenses or over the ring mirror. I haven't found a use for it so far, but is for sure useful for inspection of very flat surfaces.
Generally Epi bright field is giving low contrast images because the light passes the objective lenses twice and some is scattered. Polarisation helps a lot here. Perhaps you objective is a bit dusty or moldy, this would show heavily in Epi bright field.

What setup are you using and what are you observing?

Bob
Hello Bob!
I use this kind of metallographic microscope with illumination through a lens.
Image

It has such an optical design

Image

And I adapted Nikon BD Plan metallographic lenses to it and got an excellent result!
Now I need a lens with a maximum aperture of 1.25-1.3. But I can't find a good one.
I used normal biological lenses but the contrast is very poor.
I think I need a special lens designed for reflective light that transmits light well in both directions.
I think these lenses have anti-reflective coatings on both sides.

LouiseScot
Posts: 1167
Joined: Tue Jul 07, 2020 1:51 pm
Location: Scotland

Re: Oil immersion lens for reflected light!

#10 Post by LouiseScot » Wed Apr 14, 2021 11:19 am

Anton77976 wrote:
Wed Apr 14, 2021 11:16 am
MicroBob wrote:
Tue Apr 13, 2021 6:00 am
Hi Anton,
I have a Zeiss Epiplan HD 100 /1,25 oil Epi bright/dark field objective. Illumination is by means of the Epi condenser from above, either through the objective lenses or over the ring mirror. I haven't found a use for it so far, but is for sure useful for inspection of very flat surfaces.
Generally Epi bright field is giving low contrast images because the light passes the objective lenses twice and some is scattered. Polarisation helps a lot here. Perhaps you objective is a bit dusty or moldy, this would show heavily in Epi bright field.

What setup are you using and what are you observing?

Bob
Hello Bob!
I use this kind of metallographic microscope with illumination through a lens.
Image

It has such an optical design

Image

And I adapted Nikon BD Plan metallographic lenses to it and got an excellent result!
Now I need a lens with a maximum aperture of 1.25-1.3. But I can't find a good one.
I used normal biological lenses but the contrast is very poor.
I think I need a special lens designed for reflective light that transmits light well in both directions.
I think these lenses have anti-reflective coatings on both sides.
Wish you'd said that before!
Louise
A Nikon CF plan 20x; A Swift 380T; A DIY infinity corrected focus rail system with a 40x/0.65 Olympus Plan, a 10x/0.30 Amscope Plan Fluor, and a 20x/0.75 Nikon Plan Apo

Anton77976
Posts: 6
Joined: Wed Apr 07, 2021 6:04 pm

Re: Oil immersion lens for reflected light!

#11 Post by Anton77976 » Wed Apr 14, 2021 11:37 am

LouiseScot wrote:
Mon Apr 12, 2021 8:49 pm
Anton77976 wrote:
Mon Apr 12, 2021 8:26 pm
Thanks Louise!
Perhaps I put it wrong, by reflected light I mean not a dark field, but lighting through an illuminator.
I already have several MSPlans and NIKON M Plan and I really like how they work, but their maximum aperture is 0.9 - 0.95.
I want more resolution and I am using biological lenses, but the result is not perfect, I get very low contrast.
I think the reason is inappropriate enlightenment of such lenses.
I understand that the Olympus M Plan 100 HI 1.25 is outdated, but I can't find any new 1.25 aperture lenses.
And I do not understand why this is happening? Am I bad at searching or is oil not used in metallography?
Reflected light means bouncing light off a target as opposed to transmitting light through it. To the best of my knowledge there aren't any low-cost larger aperture non immersion objectives. The close working distances require an immersion medium. I believe metallurgic objectives are designed to not use a coverslip?
https://www.nikonmetrology.com/images/b ... ght-en.pdf

Louise

ps I can't see how you could use reflected light with an immersion medium which assumes transmitted light - just not possible
Louise! I just need an oil immersion lens that works without a coverslip. The light from the lamp passes through the objective to the object, and then returns to the eyepiece, I think the oil should not interfere with this process.
Now I have ordered this lens, maybe it will suit me.
https://www.ebay.com/itm/Carl-Zeiss-PLA ... OSwEOhfZIC~

Anton77976
Posts: 6
Joined: Wed Apr 07, 2021 6:04 pm

Re: Oil immersion lens for reflected light!

#12 Post by Anton77976 » Wed Apr 14, 2021 11:46 am

LouiseScot wrote:
Wed Apr 14, 2021 11:19 am
Anton77976 wrote:
Wed Apr 14, 2021 11:16 am
MicroBob wrote:
Tue Apr 13, 2021 6:00 am
Hi Anton,
I have a Zeiss Epiplan HD 100 /1,25 oil Epi bright/dark field objective. Illumination is by means of the Epi condenser from above, either through the objective lenses or over the ring mirror. I haven't found a use for it so far, but is for sure useful for inspection of very flat surfaces.
Generally Epi bright field is giving low contrast images because the light passes the objective lenses twice and some is scattered. Polarisation helps a lot here. Perhaps you objective is a bit dusty or moldy, this would show heavily in Epi bright field.

What setup are you using and what are you observing?

Bob
Hello Bob!
I use this kind of metallographic microscope with illumination through a lens.
Image

It has such an optical design

Image

And I adapted Nikon BD Plan metallographic lenses to it and got an excellent result!
Now I need a lens with a maximum aperture of 1.25-1.3. But I can't find a good one.
I used normal biological lenses but the contrast is very poor.
I think I need a special lens designed for reflective light that transmits light well in both directions.
I think these lenses have anti-reflective coatings on both sides.
Wish you'd said that before!
Louise
Sorry Louise!

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Oil immersion lens for reflected light!

#13 Post by MicroBob » Wed Apr 14, 2021 12:21 pm

Hi,
your setup looks good and should work well. The tube length will be over 160mm so without intermediate lenses that compensate for this 160mm objectives won't give a good image and be parfocal.
Your setup could be able to provide Epi dark field but your objectives are only for bright field. Here polarisation would help a lot.

Bob

Anton77976
Posts: 6
Joined: Wed Apr 07, 2021 6:04 pm

Re: Oil immersion lens for reflected light!

#14 Post by Anton77976 » Wed Apr 14, 2021 3:05 pm

MicroBob wrote:
Wed Apr 14, 2021 12:21 pm
Hi,
your setup looks good and should work well. The tube length will be over 160mm so without intermediate lenses that compensate for this 160mm objectives won't give a good image and be parfocal.
Your setup could be able to provide Epi dark field but your objectives are only for bright field. Here polarisation would help a lot.

Bob
Thanks Bob.
I change the length of the tube 160 or 210 depending on the lens. I add a lens if the lens is adjusted to infinity, this is not a problem!
The problem is finding a suitable lens with a 1.25-1.3 aperture that can work in a light regiment without a drop in contrast.
I'm looking for a lens!

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patta
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Re: Oil immersion lens for reflected light!

#15 Post by patta » Mon Jun 07, 2021 9:34 pm

I've seen several bit old Zeiss Jena Planachromat 100x oil, usually infinite, no coverslip, at reasonable prices. They tend to have a nasty M19 screw instead of RMS (WHY??) and you should find their compensating eyepiece.
May fit your bill for reflected illumination.
Also maybe a simple achromat (non-plan) could work well, since they have few lenses, so less reflections, better contrast than Plan or planapos.

Phill Brown
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Re: Oil immersion lens for reflected light!

#16 Post by Phill Brown » Mon Jun 07, 2021 10:52 pm

Zeiss is Euro metric.
RMS is UK?

Could go from RMS nose thread to metric lens with a converter?.

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patta
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Re: Oil immersion lens for reflected light!

#17 Post by patta » Wed Jun 09, 2021 7:01 am

Phill Brown wrote:
Mon Jun 07, 2021 10:52 pm
Zeiss is Euro metric.
RMS is UK?

Could go from RMS nose thread to metric lens with a converter?.
Zeiss(es) made items of more or less any sizes and units; two centuries ago UK was ruling in microscopy (and thread-cutting), so the UK's RMS objective thread (W 0,8" x 36 tpi) imposed itself and it is still today the standard for Zeiss and other manufacturers. At the time each single town in Germany had its own different "Zoll" (inch) and screw compatibility was a nightmare; so they agreed on a foreign unit.
Even Nachet manufactured with the RMS thread, in Paris!! They probably used RMS thread objectives to measure accurately the standard Meter. Weird world.
Maybe at some point they have ISO-metric-ized the RMS thread and call it 20.50 x 0.70 55°. The thread angle unit is still Babylonian however.
Even after Brexit, there are a few pubs in the Continent where you can order "one Pinte" of beer, in spite of all the metrologist's standardization efforts. Where in London, the half-liter is strictly banned; but you can get an ISO Liter.


Yes you can convert the thread, the Belarusian of Rafcamera are the (only?) with stock, 30$ per ring. They have M19-RMS both flangeless (same parfocal distance) and with some 15mm flange.
If you go vintage, may look also at the Lomo objective, for sure they made some specific for oil immersion reflected light. With English RMS thread: in Russia they have been using English inches since long time.

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