Water objective advice needed....

Everything relating to microscopy hardware: Objectives, eyepieces, lamps and more.
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neal Shields
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Water objective advice needed....

#1 Post by neal Shields » Mon Dec 05, 2022 11:33 pm

You guys got me looking at water objectives. I hate cleaning up oil and I like to be able to just sit down for 5 or ten minutes at a time.

My main microscope has a 5 turret condenser with: ph2,ph3,DIC10, DIC40, and DIC100 prisms. If that wasn't the case I would probably look at 60 power objectives either water or dry but I like the idea of keeping my DIC capability in what ever new lens I get if I get one. My current objectives are all phase semi-apocramatic so I am lusting for something that is APO.

If I stay with Olympus at 40x I can only find one lens that gives me significantly more non-oil capability than I already have: UAPO/340 40x water Na 1.15. Some of you might have noticed that it isn't a Plan lens. I have NO experience with non plan lenses. It is optimized for fluorescence microscopy and at this time, I have no intention of ever doing that. So it will be brightfield and DIC. With a1.15 NA the formulas would suggest that I can use a good 20x eyepiece and get close to my 100x oil magnification?

My current camera set up crops about 3/4 of what I see in the eyepiece out so I am thinking that, at least for photography, the fact that it isn't plan won't make any difference.

My other option would be a dry 60 or 80x but I wouldn't have DIC capability. My current DIC is marginally limited by the fact that I am using phase objectives that although rated for DIC they are rated as "limited".

Comments and suggestions appreciated.

Thanks
Neal

Dennis
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Re: Water objective advice needed....

#2 Post by Dennis » Mon Dec 05, 2022 11:49 pm

Neal,
4 or 5x, 10x, 20x, 40x

I am ordering a cheap (20 bucks) 1x from Amazon but coming straight from China.
I hope it works half good or better cause I need a "larvae" and "aquatic worm" and large copod cyclops etc... objective.

large larvaes and worms will eat a 4x right up and you won't even see half of them!

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Re: Water objective advice needed....

#3 Post by PeteM » Tue Dec 06, 2022 12:42 am

Lots of ways to go, Neal. Some other possibilities:

1) Phase condensers are relatively cheap, so you could move your phase annuli to a phase condenser and have more open spaces for DIC at other magnifications.

2) I'm not sure that water immersion objectives are the holy grail they might seem. Many of the Olympus ones (and pricey at that) are meant to be dipped for electophysiology research. There are the Chinese ones, but not of superb quality. In either case, you may have trouble finding an affordable (in the Olympus WI case) or matching (in the third party WI case) DIC prism.

What is usually of superb quality is a 60x Plan Apo oil objective with a 1.4na. These will typically see further under the coverslip than a 100x Plan Apo oil and (with the right prism) provide superb DIC.

This leaves the inconvenience of adding a drop of oil to the coverslip, blotting the lens in between moves back to dry 40x, and cleaning it off at the end. The difference between adding a drop of distilled water, blotting the lens in between, and then cleaning it off later is only a few more seconds for oil. Furthermore, any mineral contaminants carelessly left to dry in water are likely to adhere even more tenaciously than weeks-old immersion oil.

A water immersion objective gives you an image not nearly as good as your 100x plan fluorite. A 1.4na 60x plan apo puts you near the practical limits of optical resolution.

3) As others have said in your previous thread, 20x is a useful magnification - especially if it's a full plan fluorite or plan apo. Ideal for protists and most plant cells. Enough depth of field to often have many specimens appear sharper than at 40x, without focus stacking. Enough NA and resolution to push the magnification to around 750x. You might also be surprised at how much better a 20x DIC image with a Plan Apo objective looks than a 20x DIC image with a phase contrast "universal" Plan Fluor.

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Re: Water objective advice needed....

#4 Post by Dennis » Tue Dec 06, 2022 12:52 am

Oh you said water immersion objectives.
I just read in my mind "water samples- pond microbes etc"

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Re: Water objective advice needed....

#5 Post by apochronaut » Tue Dec 06, 2022 3:30 am

Water immersion objectives solve one problem that isn't readily observed by the average amateur microscopist. They can be forgiven for interpreting the problem of loss of resolution in depth, as being a normal aspect of viewing live water samples. That only happens with oil immersion objectives.
Water immersion provides better resolution in depth, than oil immersion : so despite the obvious difference betwen a high grade oil immersion objective of around 1.30 N.A. compared to a high grade water immersion objective at around 1.15 N.A. , in viewing an aqueous sample in depth the water immersion objrctive can excell over the oil immersion objective.
Obviously , the degree of colour correction of each objective is important . It is unfortunate that better colour corrected versions of water immersion objectives at lower pricess are not manufactured.

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Re: Water objective advice needed....

#6 Post by Macro_Cosmos » Tue Dec 06, 2022 11:53 am

1) Go for the UPlanSapo 60xW and get the pairing prism. Stay away from that 40x.
2) What is your DIC slider? The 40x needs BFP1 position, U-DICT will theoretically yield subpar results.

40x using fluorescence beads, see how bad the periphery is yourself.
Image

60x, even with a punishing 2x projection eyepiece, which means the corners are technically outside of the objective's "comfort zone".
Image

It absolutely does show up in imaging.
Image

(Outdated) article reporting on the distortion.
Objective itself is a terrific performer if you simply do not care about plan correction. 40x at 1.15NA also allows oil immersion darkfield, cannot do that with 1.2.
https://macrocosmosblog.wordpress.com/2 ... decentred/
apochronaut wrote:
Tue Dec 06, 2022 3:30 am
Water immersion provides better resolution in depth, than oil immersion : so despite the obvious difference betwen a high grade oil immersion objective of around 1.30 N.A. compared to a high grade water immersion objective at around 1.15 N.A. , in viewing an aqueous sample in depth the water immersion objrctive can excell over the oil immersion objective.
This is absolutely the case and abundantly clear with thicker samples.
Obviously, if the sample is thin enough and adhered directly underneath the coverslip, a high-end oil immersion objective coupled with an oiled condenser will yield a greater resolution. However, most samples are just not like that.
The disadvantages are the price ($$$$$) and the water evaporates. For what it is worth, the correction collar needs to be adjusted for optimal results as well.

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Re: Water objective advice needed....

#7 Post by ldflan » Tue Dec 06, 2022 3:12 pm

I assume you are asking about infinity corrected objectives? If not, the Lomo water immersion objectives, though very old designs in fragile mounts, might meet your wants.

The ones I know of are these:

85x 1.0
70x 1.23 Apo
65x 1.1 Apo
60x 1.0
40x 0.75
30x .65-0.9

There are almost certainly others.

Of these, I can personally recommend the 30x with the iris- a very nice objective for darkfield use especially. The 70x 1.23 is good. My 65x is probably a bad sample.

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Re: Water objective advice needed....

#8 Post by neal Shields » Tue Dec 06, 2022 3:58 pm

GREAT INFORMATION!

I especially appreciate the photographic examples.

The one with the dots gives me pause.

My slider is the U-Dict, not the "s" however elsewhere on this site (what a great resource) someone that owns both says he can't tell the difference between the two with an objective that "requires" the "s".

I hadn't thought about the water drying up! With DIC I am usually at max illumination so I will have to run an experiment to see how long it takes to dry.

I suspect that the main purpose of this lens would be to look at pond water and live critters.

I am thinking that in this application so much is at different depths anyway that the fact that it is not Plan would not be as noticeable.

If I stay with 40x or 100x Olympus has very few DIC recommended objectives with any working distance.

Still noodling thanks for all the input.

Neal

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Re: Water objective advice needed....

#9 Post by PeteM » Tue Dec 06, 2022 6:21 pm

Somewhere Olympus has an excellent article on the uses of water dipping and water immersion objectives. It's worth a read.

I'm not really sure that what you want to do is a match? Probably not live cell physiology, combined fluorescence imaging of live cells in aqueous mounts? Protists, probably yes. But those image well captured in a thin stratum of water under a cover slip and with 20x to 40x DIC objectives. Witness numerous videos here and elsewhere.

There's improvement with a 60x water immersion objective if live cells are your thing, with water above the cover slip (still a bit messy). However (Macro-Cosmos likely knows) that UPlanSApo 60xW objective probably sells well above $5K - and more for the DIC prism. You can likely find a lesser 60x W objective out of China for much less, but not likely an Olympus compatible prism for it?

Trying to track protists with a water dipping objective is more problematic. Even with that deeper view, in a deeper water layer they'll dart in and out of view. Instead, those are better for things like brain tissue that more or less stays put.

FWIW, I ended up with an Olympus water dipping 60x objective (LUMPlanFl 60x 0.90 W) out of a trashed confocal setup and at a great price. It even provides a decent image, misused, with a drop of water above a cover slip. One of these days I may find a good use for it . . .?

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Re: Water objective advice needed....

#10 Post by zzffnn » Tue Dec 06, 2022 9:39 pm

The (finite 160mm tube length) LOMO 60x 1.0 is a water dipping objective, and not very good for immersion.

My 65x provides more contrast than my 70x and a bit longer working distance. 70x is not easy to use with thicker samples, even for a microscopist with professional microbiology training like me.

I recommend the 30x as well, along with 65x.

40x has too much working distance and is primarily designed for dipping. At NA 0.75 though, it still performs great with water immersion. But with water immersion, you may have to put too much immersion water to join the 40x with cover slip, such that it floods away your sample.

I have not used 85x, but suspect that its short working distance and high magnification (coupled with achromatic correction) would not make it easy to use.

If your subject is in water, it really helps to have 30/40x and 60x water objectives. Oil objective will work but does not view as deeply or clearly as water objectives, when a live subject is in deep water mount. LOMOs are so cheap that you can easily get another scope to dedicate to their use.

If you only view mounted (dead) subjects (such as mounted diatoms) though, don’t bother with water objectives. Oil objectives are better in that application.

I suspect PZO DIC will work with LOMO water objectives (for example on a DIY Olympus BH2 trinicular scope), though I have not had time to finish my DIY to be sure. Paul Martin told me Zeiss (160TL) DIC does not work well with the LOMO 70x 1.23.

LOMO offered a nice apo 60x oil iris objective too, which can sit on the same objective turret with other water objectives, for darkfield and higher magnification. Suck away immersion water with cotton swap and switch to oil is easy (though you won’t be able to switch from oil immersion back to water immersion).

Plan correction is not really necessary, if your subject is alive and never stops for portraits.

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Re: Water objective advice needed....

#11 Post by Macro_Cosmos » Wed Dec 07, 2022 10:42 pm

PeteM wrote:
Tue Dec 06, 2022 6:21 pm
There's improvement with a 60x water immersion objective if live cells are your thing, with water above the cover slip (still a bit messy). However (Macro-Cosmos likely knows) that UPlanSApo 60xW objective probably sells well above $5K - and more for the DIC prism. You can likely find a lesser 60x W objective out of China for much less, but not likely an Olympus compatible prism for it?
The UPlanSApo 60xW is around $8,000. There is a special version for deconvolved confocal/superresolution that edges $10,000.
The U-DIC60 normal prism is around $600, HR and HC variants are $800.
Evident decided it was a neat idea to discontinue all oil immersion top lens prisms. I will never stop whining about this.

There is no "Chinese alternative" of water immersion/water dipping objectives, a commercial one simply does not exist. There are Chinese microscopy systems that use such objectives, however, it is either made by Nikon or Evident.
zzffnn wrote:
Tue Dec 06, 2022 9:39 pm
If you only view mounted (dead) subjects (such as mounted diatoms) though, don’t bother with water objectives. Oil objectives are better in that application.
Depends.
Some samples are thick and combined with the preparation method, a high numerical aperture oil immersion will not produce an image.
Most truly unique and bizarre diatom slides are vintage, modern slides usually cannot offer such diversity because diatom deposits naturally deplete, gets closed off, or vanish due to urbanisation. Those vintage slides while being expertly created at that time, often fails to live up to modern standards where the frustule is adhered directly underneath the coverslip for the best results and high refractive index mountant is utilised.
neal Shields wrote:
Tue Dec 06, 2022 3:58 pm
The one with the dots gives me pause.
My slider is the U-Dict, not the "s" however elsewhere on this site (what a great resource) someone that owns both says he can't tell the difference between the two with an objective that "requires" the "s".
I hadn't thought about the water drying up! With DIC I am usually at max illumination so I will have to run an experiment to see how long it takes to dry.
I suspect that the main purpose of this lens would be to look at pond water and live critters.
I am thinking that in this application so much is at different depths anyway that the fact that it is not Plan would not be as noticeable.
Those fluorescence beads are pretty damning but I doubt anyone does "tiny balls microscopy" anyway. The distortion can be ignored if you are chasing live pond critters. The primary use of that 40x is calcium imaging and the most important aspect is high transmission at UV wavelengths, people can care less about their beads being turned into comets since they can just use a region of interest to cut the nastiness out.
I am naturally very sceptical of the claims that BFP1 does not matter, I will have to try it out myself. It could be negligible for one prism-objective combination, does that mean it is negligible for all?
If you are worried about water drying out and would rather not invest in some clunky water dispensing system, you can use Genteal gel, available from a supermarket or any pharmacy.

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Re: Water objective advice needed....

#12 Post by Scarodactyl » Thu Dec 08, 2022 12:02 am

Macro_Cosmos wrote:
Wed Dec 07, 2022 10:42 pm
Evident decided it was a neat idea to discontinue all oil immersion top lens prisms. I will never stop whining about this.
Olympus did what Evidon't.

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Re: Water objective advice needed....

#13 Post by apochronaut » Fri Dec 09, 2022 4:15 pm

[quote=Macro_Cosmos post_id=130582 time=1670452974 user_id=3511
There is no "Chinese alternative" of water immersion/water dipping objectives, a commercial one simply does not exist. There are Chinese microscopy systems that use such objectives, however, it is either made by Nikon or Evident.
[/quote]

There are 3 types of commercial Chinese water immersion objectives available that I know of. All are planachro and corrected for a .17 cover slip. Presumably, they would also work uncovered with certain flat solid samples uncovered too. I haven't tried them in that application.
1) 100X 1.15 infinity corrected for a 180mm reference length ( Olympus ). Probably made by Motic.
2) 100X 1.10 infinity corrected for a 200mm reference length, R.M.S., 45mm parfocal. ( Nikon) . Not made by Nikon.
3) 100X 1.10 infinity corrected for a 200mm reference length, 25mm , 60mm parfocal. (Nikon) . Not made by Nikon.

There are also several W.I. objectives made by Seiwa and marketed by Radical in India. A 60X planfluor sticks in my mind as one of them but the last time I checked , it was unavailable. It is possible that the design exists and available on a minimum order basis. Radical seems to keep low quantities of stock.

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Re: Water objective advice needed....

#14 Post by apochronaut » Thu Dec 15, 2022 10:11 pm

I finally found a minute to post images of the three mentioned above.
Attachments
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Re: Water objective advice needed....

#15 Post by Macro_Cosmos » Thu Dec 15, 2022 11:25 pm

I have seen the NexScope one, the other two are new to me, thanks for sharing. My guess is they are sort of modified oil immersion objective where the glass placement is appropriate for the refractive index of water rather than oil, and therefore they are not comparable to what the big 4 offers. I have only seen engineering copies of water immersion and dipping fluorite/apochromatic objectives from Chinese manufacturers. The water dipping ones are not that expensive, so I cannot see much of a competitive edge. Unless they can offer for example a 10xW fluorite for $300-$500 (new is around $800), I find it hard to give them a try. Hopefully this is possible, budget water dipping objectives should be very good as a lightsheet scanning objective.

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Re: Water objective advice needed....

#16 Post by woyjwjl » Fri Dec 16, 2022 3:48 am

neal Shields wrote:
Mon Dec 05, 2022 11:33 pm
You guys got me looking at water objectives. I hate cleaning up oil and I like to be able to just sit down for 5 or ten minutes at a time.

My main microscope has a 5 turret condenser with: ph2,ph3,DIC10, DIC40, and DIC100 prisms. If that wasn't the case I would probably look at 60 power objectives either water or dry but I like the idea of keeping my DIC capability in what ever new lens I get if I get one. My current objectives are all phase semi-apocramatic so I am lusting for something that is APO.

If I stay with Olympus at 40x I can only find one lens that gives me significantly more non-oil capability than I already have: UAPO/340 40x water Na 1.15. Some of you might have noticed that it isn't a Plan lens. I have NO experience with non plan lenses. It is optimized for fluorescence microscopy and at this time, I have no intention of ever doing that. So it will be brightfield and DIC. With a1.15 NA the formulas would suggest that I can use a good 20x eyepiece and get close to my 100x oil magnification?

My current camera set up crops about 3/4 of what I see in the eyepiece out so I am thinking that, at least for photography, the fact that it isn't plan won't make any difference.

My other option would be a dry 60 or 80x but I wouldn't have DIC capability. My current DIC is marginally limited by the fact that I am using phase objectives that although rated for DIC they are rated as "limited".

Comments and suggestions appreciated.

Thanks
Neal
I want to deviate from the theme a little. Generally speaking, the non detachable prism (such as the five holes you said) does not fit the APO objective lens (what you expect, isn't it?). Please find your DIC kit manual

I'm very curious. Nobody noticed this in the above discussion
Micrographers from China, thanks to the forum for providing a platform for exchange

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Re: Water objective advice needed....

#17 Post by neal Shields » Sun Dec 18, 2022 1:21 am

https://www.flickr.com/photos/196001110 ... ed-public/

I got it! Thanks to everyone for the advice. It is 40x NA 1.15 APO.

Even though it has a back focal distance that isn't supposed to be compatible with my non shift U-DICT slider it seems to work fine (as someone here already said).

The fact that it isn't Plan is not as yet a noticeable concern.

My main problem is mine not the lenses. It has a correction collar and I can't figure out how to set it. No problem if you know the thickness of the cover slip but I don't. If I focus and move the correction setting it goes out of focus so I know it is doing it's job, But to my old eyes I can move it to either extreme and focus and I can't tell the difference.

I will report more as I learn more.

Thanks again to everyone.

Neal

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Re: Water objective advice needed....

#18 Post by woyjwjl » Mon Dec 19, 2022 1:27 am

neal Shields wrote:
Sun Dec 18, 2022 1:21 am
https://www.flickr.com/photos/196001110 ... ed-public/

I got it! Thanks to everyone for the advice. It is 40x NA 1.15 APO.

Even though it has a back focal distance that isn't supposed to be compatible with my non shift U-DICT slider it seems to work fine (as someone here already said).

The fact that it isn't Plan is not as yet a noticeable concern.

My main problem is mine not the lenses. It has a correction collar and I can't figure out how to set it. No problem if you know the thickness of the cover slip but I don't. If I focus and move the correction setting it goes out of focus so I know it is doing it's job, But to my old eyes I can move it to either extreme and focus and I can't tell the difference.

Neal
If the mechanical tube length is correct, the rear focal plane should not be a problem

Some lenses of APO objective lens in BH2 era will destroy polarization, at least in my SPLANAPO 100X(NA correction collar). The phenomenon is uneven background

I'm curious about your 40X objective lens. What's the specific model?

The thickness of the cover glass is measured by an outside micrometer, which can be purchased cheaply in the Chinese market,According to my experience, it is most appropriate to adjust the collar not according to the thickness of the cover slip. Yes, adjusting the collar will lead to refocusing, but you will find that CA will be significantly improved at a certain position.
Micrographers from China, thanks to the forum for providing a platform for exchange

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Re: Water objective advice needed....

#19 Post by neal Shields » Mon Dec 19, 2022 9:47 pm

Report after a couple of days.

One of the main questions was could I use an objective with a back focal plane of -25 with a slider (U-DICT) that was made for a -19?

I would say yes. I took two photographs with exactly the same DIC slider settings. One with the UAPO 40x water and one with a UplanFL PH 40x

If anything I like the "wrong" one better but that may be because of the phase ring in the -19 lens.

Uplan fl ph -19 bfd
https://www.flickr.com/photos/196001110 ... ed-public/

UAPO/340 water -25 bfd
https://www.flickr.com/photos/196001110 ... ed-public/

The second, new to me feature, is the correction collar. It definitely makes a difference but dialing it in is fiddly and you have to have a good memory as sometimes the differences are subtle. All the instructions say set it close, focus, and move the collar slightly. Then move the collar slightly and focus again. Repeat...

The following are two pictures one as close as I could get it with my old eyes and the other as far away as possible;

https://www.flickr.com/photos/196001110 ... ed-public/

https://www.flickr.com/photos/196001110 ... ed-public/

As usual I can't quite capture everything in the photos, I see through the eyepiece but my plan in the future is to use a micrometer (I have one that is for checking paper thickness that is quick and prefect) I will measure the difference between the base slide and the cover glass and the medium and then just set it for thin, normal, thick, very thick and as my mentor said: "go down life's road".

Maybe if I get good enough to enter Nikon's small world contest I will dial it in perfectly but until then it will have to be "close enough for government work".

Neal

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Re: Water objective advice needed....

#20 Post by Macro_Cosmos » Mon Dec 19, 2022 10:43 pm

neal Shields wrote:
Mon Dec 19, 2022 9:47 pm
If anything I like the "wrong" one better but that may be because of the phase ring in the -19 lens.
Which prisms are you using? They both look incompatible, though the DIC effect is solid so I would say it does not matter too much. If none of the prisms are compatible, the comparison is misleading.
The 40x FL is UIS or UIS2? Does it have the "N" mark?
I assume the 40x is the UApo 40xW 340, I have only seen one with the "N" and I am the one selling it on eBay.

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Re: Water objective advice needed....

#21 Post by neal Shields » Tue Dec 20, 2022 4:13 pm

The prisms are U-DP-40 and U-DICT. The condenser is a BX-UCDB

The condenser instructions show this as the correct configuration for a UPlan Fl 40x objective. (However, my microscope was configured in the late '90s and current production may be different.)

My dry objective is a UPlan FL 40X Phase which is technically wrong. So even my dry is not optimal.

Olympus says that the non-phase lens of this type is "excellent" for transmitted DIC, and they characterize the Phase lens as: "Limitation".

As an aside: I also dabble in large format photography. If you go to the Schneider web site for large format lenses, you almost have to have a Phd in optics to understand the objective data they provide before making a decision. I.E. there are graphs that tell you the modulation transfer function for each lens at every distance from the center to the edge of the image circle. In microscopy, they seem to be very good at subjective information. I.E. "limitation" vs "excellent".

However while i don't have a non-phase Uplan FL in 40x I do have both a Uplan FL ph 10X and a Uplan FL 10X and I don't notice any difference between them in DIC performance.

Micro Cosmos...I looked at your lens before I purchased this one. There were 4 available on line that I could find. I bought the cheapest as I couldn't even rationally justify that. Beyond that I didn't want to risk it getting lost from Australia and wasn't eager to invite dealings with US Customs. (As an aside, even from a US shipper, it got lost. They delivered it to a neighbor two houses down and across the street. "Signature required" doesn't seem to mean the recipient's signature.

What I have noticed since the prior post is that the difference between a -19 back focal distance lens and a -25 BFD lens seems to be the width of the color bands as you turn the DIC slider control. With the dry lens I can get almost all of the field of view black at once. With the water lens I get a black band that is about 1/3 of the field of view. I can't show this with my current set up because my microscope camera crops out about 2/3s of the field.

Much of what is wrong with my DIC photos could possibly be operator error.

The microscope was configured by a research scientist and with the exception of the new objective, is just as it came from Olympus. The compromise of using a Phase lens for DIC was probably driven by the fact that when it was ordered I don't think an 8 place condenser turret was available, so if he wanted quick and easy change over from phase to DIC he only had one objective option Uplan FL phase.

(This is the main reason I didn't take your suggestion to get a 60X as I am facing the same constraints now 30 years later, that he was then. Going to a 60X would require either giving up current capability or buying the new 8 position condenser and an additional 60X DIC prism. I don't know how easy it is to break a DIC prism (olympus says use a balloon to clean them) but even if I didn't mind the hassle, I don't like the idea and risk of taking DIC prisms in and out of the condenser.)

As it is he had to use the 100X DIC prism position for bright field, which is actually recommended in my condenser manual.

And lastly, I think my new lens and all of my old ones are UIS NOT UIS2

Again, however, I looked at that and could find NO objective data that indicated the difference. I used to run an engineering department that sold to the major car companies. They demanded data not opinions. I think Olympus would be lost in that environment.

Neal

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Re: Water objective advice needed....

#22 Post by viktor j nilsson » Tue Dec 20, 2022 4:34 pm

neal Shields wrote:
Tue Dec 20, 2022 4:13 pm
The prisms are U-DP-40 and U-DICT. The condenser is a BX-UCDB

What I have noticed since the prior post is that the difference between a -19 back focal distance lens and a -25 BFD lens seems to be the width of the color bands as you turn the DIC slider control. With the dry lens I can get almost all of the field of view black at once. With the water lens I get a black band that is about 1/3 of the field of view. I can't show this with my current set up because my microscope camera crops out about 2/3s of the field
That is exactly what you expect with a mismatched dic setup. And that's why Olympus doesn't recommend this combination. DIC backgrounds will always show a little gradient, but a matched set should be fairly even over the entire field. But a lot of people (me included) use mismatched combinations and try to live with uneven backgrounds. But to me, a 1/3 fov black band seems pretty bad, and borderline tolerable. Can you snap a phone image through an eyepiece?

Also, if you're interested, I have a UPlanFl N 40x on eBay (located in Sweden). Happy to give a discount to a forum member, especially if I don't have to pay ebay's fees.

neal Shields
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Re: Water objective advice needed....

#23 Post by neal Shields » Tue Dec 20, 2022 8:10 pm

These are full field of view taken with my cell phone. I tried to pick a subject that would demonstrate the banding.

The banding is most pronounced when you use DIC to replicate dark field. I also did a shot with the -25 BFL (Uapo/340 water) lens with what I would call normal DIC. Enhanced 3d contrast but normal coloring. In that case (in my opinion) there is no noticeable difference.

https://www.flickr.com/photos/196001110 ... ed-public/

https://www.flickr.com/photos/196001110 ... ed-public/

https://www.flickr.com/photos/196001110 ... ed-public/

In my opinion if you were starting from scratch paying a little extra for a U-DICTS over a normal U-DICT would make sense. However, I think you would have to be very rich (or very OCD) to buy a U-DICTS if you already had a U-DICT.

viktor j nilsson
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Re: Water objective advice needed....

#24 Post by viktor j nilsson » Tue Dec 20, 2022 8:28 pm

With so little background visible, it's very hard to judge. But I share your experience, the unevenness is especially pronounced at maximum extinction. And that's where you really see if a system is perfectly aligned. When it's mismatched, you get a black band travelling across the fov. When it's matched, you get a dark extinction cross that rolls into the fov from four corners and fills the view almost perfectly.

Scarodactyl
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Re: Water objective advice needed....

#25 Post by Scarodactyl » Tue Dec 20, 2022 9:05 pm

That all said, there'a nothing wrong with accepting good enough. You can spend a lot of time and money pursuing optical perfection.

neal Shields
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Re: Water objective advice needed....

#26 Post by neal Shields » Tue Dec 20, 2022 10:52 pm

Got off my lazy.... and put my DSLR on the microscope. It shows the full field. I decided that as I had video capability, that was the best way to show the results.

This is a -25 BFP objective (UAPO/340 40X water objective NA 1.15) with a U-DP40 bottom prism and a U-DICT top slider that is designed for -19 BFP objectives.

As you can see the black band doesn't cover the full field of view but this video makes the problem look way bigger than it does with most slides.

https://www.flickr.com/photos/196001110 ... ed-public/

Hope this helps.

Neal

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Re: Water objective advice needed....

#27 Post by Macro_Cosmos » Wed Dec 21, 2022 4:17 am

nevermind
Last edited by Macro_Cosmos on Thu Dec 22, 2022 12:26 am, edited 1 time in total.

neal Shields
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Re: Water objective advice needed....

#28 Post by neal Shields » Wed Dec 21, 2022 7:47 pm

My lens does not have the "N". I thought that was the difference between a UIS and a UIS2?

I have been thinking about this.

If my lens has a BFD of -25mm and the U-DICT is set up for -19, won't I get the same optical performance if I space my objective down by 6mm?

There are spacers on eBay for about $10, that is just a bit less than $1000 or so for a used U-DICTS slider.

As it is the only water objective I have and is 40X I don't see a need for parafocality between it and my other objectives.

Some of you that understand the ray traces better than I feel free to correct me before I blow $10.

Thanks
Neal

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Re: Water objective advice needed....

#29 Post by Macro_Cosmos » Thu Dec 22, 2022 12:25 am

Your condenser prism is not even compatible.
Anyway, enjoy experimenting.

neal Shields
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Re: Water objective advice needed....

#30 Post by neal Shields » Thu Dec 22, 2022 3:32 pm

"Your condenser prism is not even compatible."

I understand that. However, what frustrates me with Olympus is the lack of data.

My understanding is that different prisms, at a given power, in this case 40x, have different beam separations (ibiology Youtube explanation). This is based on the theoretical resolution of the objective based on NA.

Presumably my prism is optimized for an NA of about 60 and using it with an objective with an NA of 1.15 will cause a loss of resolution but; how much.

Will the lose of resolution be protonate to the difference in design NA vs Objective NA? Or will it be like using a .9 NA condenser with a 1.3 NA objective. (I.E. 1.22 x wavelingth/ condenser NA + Objective NA)

In any case if I am trying to get max resolution I will probably go bright field anyway. If I want to enhance contrast (or just make it prettier) I will use the DIC prism.

My point is "compatible" is a BIG word. I am fairly sure that using my prism with my objective isn't going to short out my power supply and cause my microscope to burn up,

Olympus is the king of "weasel words", that have no measurable objective meaning.

Pardon me I was in manufacturing QA for many years and they hammered "data speak" into us.

Neal

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