60+ X dry. of what use are they?

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apochronaut
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60+ X dry. of what use are they?

#1 Post by apochronaut » Thu Dec 17, 2015 1:01 pm

This spins off from an earlier thread plus a question posed by a forum member.
It seems, that for practical purposes , a 60X or thereabouts objective is the limit that most companies historically have manufactured as dry objectives. You see the occasional 70X or even 80 but those are scarce. These are offered as high, dry accessories, and also show up in modest scholastic microscopes as a replacement for the 100x oil objective, when a 3 place nosepiece is fitted. They are almost always .80 N.A. or higher, so that in itself is good.
With very small subjects , where the finest details are being sought, a 60X( often 63) seems a logical step, giving that last easy leap before the refined and precise , albeit cluttered, immersed observation takes over. It is annoying to go back, so a high dry option is highly desirable, to possibly avoid the inevitable, however, I find I almost never use one. Occasionally, briefly, I go there, always to back off to a high N.A. 40 for a sharper more contrastier view with a broader field , before leapfrogging to full magnification, immersion.
I really does make one understand , succinctly, why immersion 60X objectives have quite taken over in modern microscopy.
Do others have a similar response to these objectives?

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gekko
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Re: 60+ X dry. of what use are they?

#2 Post by gekko » Thu Dec 17, 2015 1:56 pm

Interesting discussion. I don't have a 60x objective, but I have, in addition to the 40x dry, a 40x fluorite oil-immersion, so I can switch back and forth between the 100x and 40x oil-immersion objectives, which I have found to be a very convenient arrangement when I need to go to 100x. But it occurs to me now that since the 40x oil objective already has NA of 1.3, would I gain much by going to the 100x?

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Re: 60+ X dry. of what use are they?

#3 Post by lorez » Thu Dec 17, 2015 3:06 pm

I really does make one understand , succinctly, why immersion 60X objectives have quite taken over in modern microscopy.
It seems, that for practical purposes , a 60X or thereabouts objective is the limit that most companies historically have manufactured as dry objectives
Are you talking about immersion 60X objectives or dry 60X objectives? Am I missing something here ?

My experience involving objective choices includes a couple of scenarios from the medical community. Selection of objectives are made to facilitate the task at hand. In one case the immersion objective is avoided because of the 'fuss factor' and in another case the immersion objective is accepted because the other attributes of the objective make it an asset.

On a pathology microscope the immersion objectives are rare and the dry 60X, in varying qualities, provides the magnification necessary to make the diagnosis. On a hematology microscope the 50X oil is prominent because it offers a wider field of view which provides a quicker scan while maintaining acceptable resolution.

My personal preference as a hobby user is the dry objective... lazy me.

lorez

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Re: 60+ X dry. of what use are they?

#4 Post by apochronaut » Thu Dec 17, 2015 5:07 pm

I am talking about dry objectives but the reference to 60X immersion objectives is because they are increasing in prominence, no doubt due to their superior resolution.

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Re: 60+ X dry. of what use are they?

#5 Post by einman » Thu Dec 17, 2015 9:02 pm

I believe the usefulness is limited by the working distance. For example teh WD of a Nikon 60X planapo is only about 0.17 mm or thickness of a coverslip. This severely limits its usefulness as you need a collar to get the best image. If it is a prepared slide- a poorly prepared slide then the depth can preclude the usefulness even further.

I find the Reichert-Austria 63X to be quite good better than my 63X Leitz. The WD of the reichert-austria objective seems to be better. I also own an Olympus Splan 100X/0.95 dry objective. I find the resolution, despite the collar, to be severely limited by WD and slide/coverglass depth. In many cases the resolution is no better than a 100X/1.25 oil immmersion without the oil.

If you prepare your own slides you can choose cover slips less than 0.17 mm and take care in the thickness of the specimen.
When all falls into place it is beautiful but that is quite a rare event.
So for this reason, though I have several 60/63X objectives of various makes, I prefer a 63X immersion objective for optimal resolution.
Last edited by einman on Fri Dec 18, 2015 1:10 am, edited 2 times in total.

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Re: 60+ X dry. of what use are they?

#6 Post by wallyrut » Thu Dec 17, 2015 9:49 pm

Hi all,

I just registered on this site today, and how interesting to find this thread on a topic I have been giving some thought to lately. I have a couple of 60x plan achro objectives and use them frequently. Like apochronaut, I don't find using oil immersion too much trouble, and my 100x oil lens gets a lot of use. I've been thinking about replacing my 40x dry with a 50x oil, but I'm not using very high end equipment, (in fact my optics are DIN 160mm), so there's a very limited selection.

On the other hand, I really like having a dry 60x. On my equipment, (Motic B3 and Optika B383PL) the 60x resolves more detail than the 40x, and even with an un-oiled Abbe the images look very crisp. I've read about problems with 60x's being so sensitive to cover glass thickness and specimen depth, but I've been very pleased with the performance on almost all slides. I have never done a direct comparison between 40x with 15x eyepieces and 60x with 10x eyepieces. I also wonder if my impression would be different if I were using apochromats instead of plan achromats.

There is one area though, where I am not so happy with the 60's. I find that both the Motic and Optika 60x lenses are very prone to flare from light at the edge of the fov. btw, the objectives seem to be different in optical design. Though both are labeled plan, the Motic is much flatter. My initial impression was that both were about equal in resolution/contrast, but then I found some diatom slides where the Optika resolves details the Motic does not. I find that if I close down the field diaphragm till I'm getting some vignetting at the edge of the fov, the contrast is very good. Visually the vignetting isn't noticeable when the field diaphragm is stationary, so I accept the vignetting in return for the improved contrast. One problem might be that using an Abbe (especially un-oiled) with a high NA lens means the edges of the field diaphragm are blurred, so I cannot fully illuminate the entire fov without some light spillage past the edge. Some years back I tried a plan 60x of another brand (don't remember which one) and returned it. It was less prone to flare, but had poorer contrast and definition than the Motic 60x.

I am considering replacing the Optika 60x, if I can find an objective that is less prone to flare. I would be interested to hear what experiences others have had with dry 60X plan achros. I did find another thread discussing 60x objectives, but don't recall anyone mentioning flare issues. I'd like to find a lens (plan or standard achro) that gives me the definition/contrast of my 60x Optika but allows me to fully illuminate the fov.

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Re: 60+ X dry. of what use are they?

#7 Post by Dale » Thu Dec 17, 2015 11:48 pm

Very timely indeed. I am trying to spec out the objectives for a new scope. Most of your comments
were quite helpful, as I want to use a 60X dry plan fluor, the cost eliminates a plan apo.
The range is 4X BF achro, 10 20 and 40X phase plan fluor, and the 60X. I can do without an
oil lens if it prevents budget overruns! For me a large wd is very usefull. My "knowing person"
must be pulling his remaining hair out.
Dale
B&L Stereozoom 4. Nikon E600. AO Biostar 1820.

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Re: 60+ X dry. of what use are they?

#8 Post by charlie g » Fri Dec 18, 2015 1:15 am

I often use my Nikon Plan DL phase 40X, 60X,100X oil...even though they have lower NA than My Nikon Fluor 40X 0.85 with correction collar, or my Nikon 60X Plan 0.85 with correction collar, or my 60XPlanApo 0.95 with correction collar, or my Nikon Plan 100X 0.90 with correction collar BF contrast method objectives.

Like Lorez stated: 'different horses for different courses..hematology one combo...vrs. patho another setup of objectives. My observations are often wetmount slide preps of freshwater protists and meiofauna.

Like einman stated...devil in the details of your observed slides..with actual resolution/actual NA achieved less than a barrels engraved spec.

Thanks to zzffnn I now have a BF 'Semi Plan 60X 0.85 objective to trott out when I need a combo for this gem.

Thanks to appocronaunt, I now have a B&L 40X 4.3 mm 1.00 oil objective to trot out! I still have not given this objective a first light. all the best , charlie guevara in wierd warm finger lakes/US

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Re: 60+ X dry. of what use are they?

#9 Post by apochronaut » Fri Dec 18, 2015 1:19 am

Are you in Italy, Wallyrut?

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Re: 60+ X dry. of what use are they?

#10 Post by Dale » Fri Dec 18, 2015 1:50 am

Charlie, I am aiming for an E600. Is your 60X a Nikon Plan DL Phase also? I only saw 2 60X objectives
listed, an achromatic, and a plan fluor. I am hoping my reasoning is correct, but the fluor will have more
wd for my thicker specimens, and it would perform better at 600X than the achro. I think there is a typo
on the Nikon lens site as they say the achro wd is 30mm, and the fluor is 17mm, isn't that backwards?
Dale
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Re: 60+ X dry. of what use are they?

#11 Post by gekko » Fri Dec 18, 2015 2:22 am

Hi Dale, I assume you are talking about Nikon infinity objectives, as those are the only ones that are meant for use on the E600. I am not sure what you mean by wd of 30 and 17 mm.

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Re: 60+ X dry. of what use are they?

#12 Post by 75RR » Fri Dec 18, 2015 2:32 am

Hi Dale,
gekko partially asked what was on my mind, as I was wondering what you meant by
Charlie, I am aiming for an E600.
Are you thinking of buying a Nikon E600?
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
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Re: 60+ X dry. of what use are they?

#13 Post by wallyrut » Fri Dec 18, 2015 2:44 am

apochronaut wrote:Are you in Italy, Wallyrut?
I am in USA. New York Microscope Company started selling Optika here, some of their offerings looked interesting, and decided to give them a try. I read in one of your posts you had a good impression of Martin Microscope. I bought my Motic B3 from them. Also had a good impression. They seem to really be into microscopes, and actually are knowledgeable.

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Re: 60+ X dry. of what use are they?

#14 Post by Dale » Fri Dec 18, 2015 3:50 am

Gekko, wd is working distance.
75RR, yes indeed, but my initial budget is 5 thou, so I'm fiddling with the best blend
of optics and accessories. Totally unfamiliar with the fluor objectives, and any of their
prices. Seems like one apo lens would exceed the rest of the scope!
Dale
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Re: 60+ X dry. of what use are they?

#15 Post by apochronaut » Fri Dec 18, 2015 1:40 pm

If you insist on buying new, then you are up against it. You can blow a lot of money on just one or two optics and fluorites are no exception. As well, you are wasting your money unless you source a condenser that can drive them. That alone is going to soar over a thousand.
However , the same amount of money will go a long way on used optics. I've probably only got about 1400.00 into my big go to microscope system and it is 100 watt, trinocular, with 3 condensers(DF,1.25 W.F. abbe aspheric,1.4 N.A. ach. apl.) ,3 planapos, 2 planfluorites, 7 planachros, iris diaphragms on all the high N.A. objectives + a camera set up on the trinoc. With the exception of a few of the camera bits, those were all ebay purchases.
The microscope itself was 450.00 delivered, with 6 planachros in it and 4 extra teaching arms and heads.
Those kinds of high value for a low price purchases, are all over ebay. The only difference is, immediate gratification is seldom the case on ebay. It can be a bit of a search . It took me a year or so to put that all together but within 2 months of the original purchase, I had a 6 planachro, 1 planapo w. iris, trinocular 100 watt scope with DF and BF at a cost of 700.00.

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Re: 60+ X dry. of what use are they?

#16 Post by apochronaut » Fri Dec 18, 2015 1:50 pm

wallyrut wrote:
apochronaut wrote:Are you in Italy, Wallyrut?
I am in USA. New York Microscope Company started selling Optika here, some of their offerings looked interesting, and decided to give them a try. I read in one of your posts you had a good impression of Martin Microscope. I bought my Motic B3 from them. Also had a good impression. They seem to really be into microscopes, and actually are knowledgeable.
I've looked at N.Y. microscope but never contacted them. Being in Canada, our dollar has tanked , so bringing anything in from across the border is pretty bad these days. Martin has always steered straight and true with me. They are long time American Optical dealers, going back to 1946 I think, so they are a valuable resource for that brand but they also were Aus Jena, WIld and Leitz dealers. They have a lot of stock of parts for those.

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Re: 60+ X dry. of what use are they?

#17 Post by charlie » Fri Dec 18, 2015 3:29 pm

apochronaut wrote: However , the same amount of money will go a long way on used optics. I've probably only got about 1400.00 into my big go to microscope system
Wow, that is impressive!

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Re: 60+ X dry. of what use are they?

#18 Post by Dale » Fri Dec 18, 2015 5:39 pm

To Apo:
Oh, there is no instant gratification on this one, in fact, I only know I am getting a great windfall
in 2016, so I have time to learn. I am working with a wonderful seller to fit out a used frame.
So far, a tri-noc head, camera, and 3 plan phase obj's are all I have nailed down. I surely did
not know the fluors needed a special condenser, that would rule them out. I noted your comments
on my wish list, thanks very much.
Dale
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Re: 60+ X dry. of what use are they?

#19 Post by charlie g » Sun Dec 20, 2015 1:49 am

Wonderful conversations you spark, apocronaught...thank you.

Dale...sorry to say..I'm 160mm tube length Nikon. My next 'jump' would be for a DIC system ( so when gekko upgrades...err he might sell me his DIC setup...hint, hint!).

wallrut...yes, yes, Martin Microscope...I also can vouch for former: Mel Sobel Microscope...???now New York Microscope...I can look it up...Hicksville, Long Island,NY)...and I bought my Nikon Labophot setup from a western NY firm: Microscope Buisness...and many forum microscopists rave about Nightigale Optics in con.US.

I loved brightfield and dark field until I obtained my DL phase stand which permits all these contrast methods...I can not see ever going 'back' to a monocular or binocular head on my stands now that for years I use trinoc head stands.

But where are we with apocrounaughts original querries..what sorts of high NA dry objectives are we useing/ all the best, charlie guevara

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Re: 60+ X dry. of what use are they?

#20 Post by Charles » Sun Dec 20, 2015 3:44 pm

I have a dry Leitz 63X and a few dry Zeiss 63X but there is no comparison to an oiled 63X or any other oiled objective. I would say any oiled objective will give you a lot better image than a dry objective but you would need to contend with the messy oil clean up. I have one objective turret with 25X oil, 40X oil, 54X oil, 63X oil and 100X oil but it rarely gets used because it's such a chore to clean up.

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Re: 60+ X dry. of what use are they?

#21 Post by apochronaut » Sun Dec 20, 2015 8:15 pm

Dale wrote:To Apo:
Oh, there is no instant gratification on this one, in fact, I only know I am getting a great windfall
in 2016, so I have time to learn. I am working with a wonderful seller to fit out a used frame.
So far, a tri-noc head, camera, and 3 plan phase obj's are all I have nailed down. I surely did
not know the fluors needed a special condenser, that would rule them out. I noted your comments
on my wish list, thanks very much.
Dale
It's not that they " need" a special condenser. They will work with an Abbe 1.25 but once you spend the money on those types of optics, you would be wasting your money not actually using their capability. The difference and availability of Abbe condensers compared to oil achromats is dramatic.
It is kind of like the making of stone soup. Adding an onion made some difference but adding the beets, carrots, cabbage etc., made the actual difference necessary for it to qualify as soup.

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Re: 60+ X dry. of what use are they?

#22 Post by travis » Fri Jan 01, 2016 3:12 pm

I recently purchased a Lomo 60x.85 and a Lomo 40x.65 from an ebay seller in Armenia. They are both in excellent condition. The seller advertised them as planners. I shelled out only $47.00 for the 60x. Well priced for a Teenager on a budget ;)
I use the 40x for surfing around on Blood smears, and I use the 60x for making videos of white blood cells. As a beginner I am satisfied with the detail that the 60x gives.

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Re: 60+ X dry. of what use are they?

#23 Post by charlie g » Fri Jan 01, 2016 8:08 pm

thank you Travis for sharing the performance you experience with your objectives in wet or fixed blood mears.

charlie guevara

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Re: 60+ X dry. of what use are they?

#24 Post by kinase » Tue Jan 19, 2016 12:25 am

If I can, I try only to use oil lenses for taking pictures. I only use air lenses for checking confluence on plates really. I haven't had a chance to use it yet because I've been unable to stain my samples but I assume the Nikon A1R the facility I'm in has uses fancy glass.

The microscopes in cell culture room aren't very good though. I wish someone would let me be in charge of getting microscopy equipment for the lab, I think I could make better choices!

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Re: 60+ X dry. of what use are they?

#25 Post by billbillt » Tue Jan 19, 2016 4:08 pm

Hi Travis,

Thanks for your report... What microscope do you use?.. Do you know what the tube length is?.. My problem with Lomo objectives is I can't ever recall seeing one marked with the tube length... There are some good buys on Ebay, but I am not sure what to buy..

The Best,
BillT

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Re: 60+ X dry. of what use are they?

#26 Post by mrsonchus » Tue Jan 19, 2016 6:02 pm

Hi all, I don't know very much at all about the technicalities of lenses but I do use my HI x100 a lot. I really find it pretty easy to drop a touch of oil onto the slide, and no bother to clean it off really, takes about a minute. I always seem to get a very good resolution and a nice bright image from it, although as far as I know it's just a cheapo Chinese job, unbranded and bought new as was my 'scope.

I read recently (yesterday in fact) that practically there's a trade-off between resolution & contrast that leads to the use of objectives (specifically plan-achromatics) at about 75% of their maximum NA, as seen when setting the condenser's iris to about 75% open where 100% would be a complete match between the iris and the objective's back-plane area as viewed down an eyepiece-tube with the eyepiece removed.

The article goes on to say that an NA above 1 can't be achieved when there's an air-gap either between the top of a slide and the objective (i.e. a dry objective) or the bottom of a slide and the top-lens of the condenser - and therefore that it's better in terms of performance (i.e. image quality/resolution) to use a 0.9 NA condenser than the ubiquitous 1.25 NA as this matches the maximum (practical) NA better unless the oil x100 is oiled both above and below the slider rather than just above as I use mine, I haven't tried oiling the condenser's top yet - I'm a bit scared to do so!

Does anyone know if this is true and therefore the optimum is to either oil above and below a slide or to use a superior quality 0.9 NA condenser rather than the apparently nominal 1.25 NA version?

Anyone any ideas? Here's a link to the article:- http://www.vanosta.be/microscopy.htm
:)

p.s. What I have experienced is that it's very important indeed to optimize the flatness and thinness of a mounted slide and to maximize (within reason of course, not to the extent of obscuring desired detail) contrast within tissue with stains - a well-stained and mounted slide has by far given me the biggest boost to image quality even when compared to a step-up from one objective's power to a larger..
Last edited by mrsonchus on Tue Jan 19, 2016 6:10 pm, edited 1 time in total.
John B

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Re: 60+ X dry. of what use are they?

#27 Post by billbillt » Tue Jan 19, 2016 6:10 pm

Hi John,

Thanks for the link to this paper.. Very informative!...

BillT

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Re: 60+ X dry. of what use are they?

#28 Post by mrsonchus » Tue Jan 19, 2016 6:19 pm

billbillt wrote:Hi John,

Thanks for the link to this paper.. Very informative!...

BillT
Hi Bill, yes I found it pretty informative - but I'd really like to know if it's correct - I always exercise caution with online information sources until I find supporting information elsewhere as the quality can often be 'sub-optimal' online I find.
I'm particularly interested to know about the need to oil both surfaces of a slide with a 1.25 NA objective & condenser, and whether it's better to go for a 0.9 NA condenser instead - it seems that the more I learn the more I need to learn! :)
Then there's a corrected-condenser to consider, to match better the plan-achromatic objectives that virtually all of us use? Questions, questions... Any ideas? :)
John B

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Re: 60+ X dry. of what use are they?

#29 Post by billbillt » Tue Jan 19, 2016 6:32 pm

Thanks for the reply, John... Could you show me how to do the "quote" in a post?.. Every time I do it I screw something up... I think all of this info just shows that there is a never ending learning curve in microscopy!.. I have read here that some folks oil the condenser to the bottom of the slide.. I have never done it... I rarely use oil at all.. I am too lazy to clean up!..LOL..

BillT

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Re: 60+ X dry. of what use are they?

#30 Post by mrsonchus » Tue Jan 19, 2016 6:49 pm

billbillt wrote:Thanks for the reply, John... Could you show me how to do the "quote" in a post?.. Every time I do it I screw something up... I think all of this info just shows that there is a never ending learning curve in microscopy!.. I have read here that some folks oil the condenser to the bottom of the slide.. I have never done it... I rarely use oil at all.. I am too lazy to clean up!..LOL..

BillT
Hi Bill, when you say the quote, do you mean a quote of the post that you are responding too? In this case there's simply a button 'quote' that will enter the relevant text into your new post to-be for you. If you mean the clickable-link to say an article etc then all I do is go to the relevant web-page to which I want to post a link, highlight then 'copy' everything in the address-bar - then within my post simply click the URL button above the post-composition window and 'paste' the copied address into the space between the URL markers inserted when the URL button was clicked... Is that any help?
John B

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