60+ X dry. of what use are they?

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

#31 Post by billbillt » Tue Jan 19, 2016 6:54 pm

Hi John,
I mean like you did in your reply.. Thanks for your help... Is there anyway to maybe shorten a post and still quote it like that in the box?.. That is were it fails for me..
BillT

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

#32 Post by mrsonchus » Tue Jan 19, 2016 7:32 pm

billbillt wrote:Hi John,
I mean like you did in your reply.. Thanks for your help... Is there anyway to maybe shorten a post and still quote it like that in the box?.. That is were it fails for me..
BillT
Hi Bill, yes all you need to do is make sure the
this whatever is quoted....
markups are left alone, just edit the actual quoted message as normal, that lies between these quote start and finish markers - I do this a lot as I usually only need to quote part of a previous post - works a treat and is very handy! - and you can quote me on that! :D
John B

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

#33 Post by billbillt » Tue Jan 19, 2016 10:13 pm

Thanks, John.. I give it another try soon!...

BillT

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

#34 Post by kinase » Wed Jan 20, 2016 1:48 am

Nikon's page as well a Zeiss and Olympus and probably Leica have a bunch of pages on information about objectives and everything else they sell.

I wish I had a 63x or thereabouts oil lens. On the scope I usually use, a older Zeiss axiovert 100M I have a 40x and 100x oil that I like. On an Olympus IX73, the lenses are all air lenses but they're all fine.

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

#35 Post by apochronaut » Wed Jan 20, 2016 4:17 pm

It seems that there is a sort of sharpness quotient for each objective, that indicates performance falloff, in advance of the appearance of empty magnification and it might be fairly similar between objectives of similar specs. too. If A 40X .65 objective is used for instance, to give 400X magnification, in my experience, it never gives as defined an image as a 40X .85 objective, at the same magnification, even though the two both resolve details fairly equally. There is even a surprising improvement if the N.A is bumped to .75, even .70.

I think what I am responding negatively to here and especially with dry 60-63X objectives is a kind of composite sense of factors; sharpness, coupled with image intensity coupled with contrast that as dry objectives go up in magnification,their use can become visually uncomfortable. A 60 x .85 N.A. objective is bound to resolve two finite points better than a 40X .65, yet the image could easily have lower contrast, be darker and be less sharp and therefore be somewhat more unpleasant to use.

If a ratio of the objectives potential peak magnification , when empty magnification occurs( determined by multiplying the N.A. x 1000) to the objectives magnification were calculated : so in an average 40X case, 650/40 = 16.25 or in the case of an average dry 60x case, 850/60 = 14.17 a picture of an objectives sharpness quotient could be made, with a lower sum representing poorer all around performance. In order for a 60X to achieve a similar quotient, it would have to be about .95 or even better a 1.0( water or oil). That is pretty consistent with what I have observed with 60 or 63X objectives; that the .85 dry ones are usually a letdown, after using a good 40x .65 and especially if the 40X is .70 or higher but once the N.A. of the 60-63X gets up to 1.00, there is more consistency in the overall image quality.

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

#36 Post by charlie g » Wed Jan 20, 2016 6:32 pm

Hi, all, yes I have oiled both surfaces of my wetmount slides for 100X oil objectives...but more as an academic exercise too see how my old eyes are working.

Excellent point you raise, John B..that is unless you oil both objective to slide/ and slide to condenser face..your 'a little less' than NA 1.0. I have circa early 1900's brochures which simply state: only oiling the objective to the slide is most common practice, but in addition an oil-bridge to condenser needed for most critical work.

None of my microscopy is 'critical work', and I have not setup Kholer illumination for each objective individually, and I have not yet purchased the extra special specification (?Zeis brand slips?) 0.17 coverslips I keep meaning to purchase.

I do use my correction collars on my dry 60X objectives..and yes I enjoy the 60X no collar objective which I purchased from Fan.

With many live organisms, I enjoy 60X objective observations. Charlie guevara

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

#37 Post by travis » Thu Jan 21, 2016 12:04 pm

billbillt wrote: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
Hi Bill,
We have 2 Microscopes the one we most often use is the 1964 Olympus GB. The ocular tube Can be adjusted from 145mm to 200mm so we can use just about any objective except for infinity. The ocular tube can easily be slid out and removed to fit a 4, or 10 power objective on the end and used as a handheld microscope.
The Lomo objectives we have purchased are either advertised as Lomo/Zeiss, or the seller will sometimes list the specifications to be 160mm tube length.
Though beware there are some Lomo objectives that are 190mm T/L.
We now have 5 Lomo objectives from eBay sellers, some look new and all have good clean optics. No complaints so far.

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

#38 Post by charlie g » Thu Jan 21, 2016 2:13 pm

Charles wrote: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.
Fantastic to utilize this turrent combo you have,Charles! If I had this range of: back and forth between oiled-objective powers...the clean up would be quite tolerable for me...sigh.

Thanks to Phil, I can now toggle between 40X oil and 100X oil...but this seems a combo I have not yet setup...but your five power combo, Charles....wow!

all the best, Charlie guevara

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

#39 Post by charlie g » Thu Jan 21, 2016 2:20 pm

Hi Bill,
We have 2 Microscopes the one we most often use is the 1964 Olympus GB. The ocular tube Can be adjusted from 145mm to 200mm so we can use just about any objective except for infinity. The ocular tube can easily be slid out and removed to fit a 4, or 10 power objective on the end and used as a handheld microscope.
The Lomo objectives we have purchased are either advertised as Lomo/Zeiss, or the seller will sometimes list the specifications to be 160mm tube length.
Though beware there are some Lomo objectives that are 190mm T/L.
We now have 5 Lomo objectives from eBay sellers, some look new and all have good clean optics. No complaints so far.[/quote]


Thanks for the specifics of your two stands,Travis. I ask you..could you post the actual eBay sellers whom you had a great experience with purchaseing your LOMO objectives?

I have three LOMO objectives, all apo's...but I only intend to keep the :70X water-immersion objective (no correction collar).


Again, thanks for your microscopy posting,Travis. Charlie Guevara, finger lakes/US

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

#40 Post by billbillt » Thu Jan 21, 2016 4:39 pm

I would also like to know the name of a reliable Lomo seller..

Thanks!
BillT

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

#41 Post by travis » Fri Jan 22, 2016 2:50 pm

charlie g wrote: Thanks for the specifics of your two stands,Travis. I ask you..could you post the actual eBay sellers whom you had a great experience with purchaseing your LOMO objectives?

I have three LOMO objectives, all apo's...but I only intend to keep the :70X water-immersion objective (no correction collar).


Again, thanks for your microscopy posting,Travis. Charlie Guevara, finger lakes/US
Here are the eBay links from some sellers we have used. The last link we got a Lomo Phase turret and a Mir-4 ancillary ocular both were new and had no signs of being used. Some of the objectives also had no signs of usage and some were obviously in used condition.
The ones from Russian had rather good post times but the ones from Ukraine, and Armenia took longer to arrive. Charlie, we have not purchased any APO’s yet.
http://www.ebay.com/sch/Microscope-Part ... sn=v.s.lab
http://www.ebay.com/sch/Microscope-Part ... n=sdyu0012
http://www.ebay.com/sch/Microscope-Part ... n=14080814
http://www.ebay.com/sch/Microscope-Part ... =mucinetto

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

#42 Post by travis » Fri Jan 22, 2016 2:53 pm

Ok, Now I have a question.
This eBay seller is selling a Lomo achromat 60x 1.15 Lumin Flour, further down the page in the item specifications he list it as “ Immersion: none “ and a working distance of “ contacting “.
Is this seller listing this objective correctly? Or would this be a water or oil Immersion?
We have not bought anything from this seller yet.
Link
http://www.ebay.com/itm/LOMO-Achromat-o ... SwGotWnNvn

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

#43 Post by charlie g » Sat Jan 23, 2016 6:49 pm

Hi, Travis...to this sellers credit..the actual magnified image of the objective is clearly posted in the ad..based on this alone...I say do not purchase this item!

There is no :white color band on this objective...so I doubt it is a LOMO water immersion objective.

The seller offers very poor understanding of what he/she is selling...first the item is called a 'flour'...then at bottom a correction is made! The seller states:' contacting'..yet this seller states: 'none' for immersion.

Based on the( to my eyes)...totally asymetrical front lens (as if this lens in use was banged against a slide too hard..so front lens element is disrupted to an asymetrical appearance...to my eyes that is!...I suggest you not purchase this item.

It would be fair to contact this seller..but with the mysterious correction of what type lens unit it is...I doubt you would gain anything from a contact. all the best, charlie guevara (thanks for the seller links, Travis...and thanks Phil for tolerating this hijack of your useful thread).

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

#44 Post by einman » Thu Feb 22, 2018 8:22 pm

Continuing this discussion. I sold my Reichert 63x so Was looking for an improvment over my Leitz 63/0.85 objective. I finally found and purchased the following BEAST. Performance is better than my Reichert and previous Leitz 63x. It a takes a bit of tweaking but the images from the KK Diatom test slide are beautiful.
Image
Image

It is HUGE perhaps the largest objective I have ever seen. It is very heavy as well. The na is 0.90 a slight improvement to the 0.85 of my previous Leitz but it has a collar which allows for better resolution under a wider set of circumstances.

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

#45 Post by charlie g » Fri Feb 23, 2018 12:23 am

I'm missing something, einman (sorry)...what brand/firm is this objective you kindly show image of? What are it's specs? Have you ever tried it with live protest wetmount slide preps?

Quite a while ago in some microscopy forums...I referred to my 60X/dry with correction-collar Nikon Plan apo as an 'expresso coffee unit cylinder'...you term yours: 'the beast'!

I am very keen on hearing if you have used 'your 60X beast' with live protist wetmount slides. Charlie guevara

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

#46 Post by einman » Fri Feb 23, 2018 1:12 am

It is a Leitz 63x/0.90 Fluotar with collar. No I have not tried it with Live specimens but I did find it to be as good as my Leitz 63x/0.85 Fluotar without the collar, in terms of working distance. Resolution is better, most noticeably so with the diatom slide, but not so much when looking at standard prepared slides. Here are some other shots.

Image
Image

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

#47 Post by einman » Fri Feb 23, 2018 1:16 am

I tend to favor Apo's way of thinking in that given a choice between a high na 40X or a 63X objective I would choose the 40x. However, the price was right, so in this case I chose to have them both.

It has a good reputation so I went for it.

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

#48 Post by apochronaut » Fri Feb 23, 2018 3:06 pm

That looks to be a really beautiful objective, Everett. It should work the way a 60-63X should. Not a lot of them out there with a high enough N.A. and high optical corrections to match.
Yes, in the origins of this thread, I was thinking primarily about 60-63x .80-.85 options, which just take up space in the nosepiece, for me. Even with a 6 place , I prefer to have a 2.5X, 4X,10X,25X,40X and 100X complement; all of which I use regularly. The particular 15X eyepieces I use are those U.W.F. made by Bausch & Lomb( also branded FJW,Reichert,Leica). They have an apparent field of 25mm, so not only do I get equivalent or better performance than I would with a common 60-63X by magnifying an excellent 40X by 15X but the field is stunning and plan to the edge. Plus, I then have a total magnification range of 25X,37.5X,40X,60X,100X,150X,250X,375X,400X,600X,100Xand1500X. 1500X is o.k. with the fluorite or apochromats but is stretching it a bit with a planachro.
Subsequent to the starting of that thread, I have acquired a Reichert 63X 1.0 N.A. glyzerin immersion, notable for the fact that even without using glycerin ; using it dry, it has about the same resolution as the two Chinese made 60X ( .80 and .85) D.I.N. planachromats that also work in that infinity system. I'm pretty sure a better dry objective would give better resolution but I mention it to show that N.A. is not always the arbiter of resolution because that Reichert Glyzerin objective would be working at a severe handicap, not only in N.A. but in spherical aberration correction too.

Finding a unique and high performing dry 3mm objective is like finding a rare jewel because so many of them give bland images, stretched for resolution and contrast. Every now and then someone saw a market and justification for pulling out the stops and making fine immersion objectives. Lomo has made some truly interesting W.I. 60-70X, some of them apochromats, there are those 60X 1.4 oil immersion objectives that all of the old guard makers have dribbled out over the years, Spencer had a 60X 1.25 oil achromat, that performs like a fluorite, which I have only ever seen one of, Reichert Glyz. immersion 63X and a few others but a high dry 63X is uncommon and certainly would be nice to have. All immersion forms are annoying, not just oil because it is really difficult to get clean enough for a review, if need be.

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

#49 Post by MicroscopyUniverse » Wed Nov 24, 2021 11:24 pm

Hi all,

Because latest message mentioned Lomo water immersion objectives, my experience with them may help all forum members.

I have 3 Lomo Water immersion 40x(0.75), 60x (NA 1.0) and 65x (AN 1.1) apochromatic objectives. I bought them from ebay like new and unused. No delamination and clear optics in my case but
be careful before purchase any old Apo objective from brands such as Lomo or Zeiss/Jena. Ask the vendor about delamination.

The 40x performance is much superior than the usual Lomo achromatic 40x (A.N. 0.65) when observing pond water. Sharper images and null refraction.

The 60x is made for use it without coverglass but it performs good with coverglass.

The 65x is a beast ! very sharp images and it performs with better resolution than the 60x

I use all 3 (they are water immersion) perfectly to observe protozoa in pond water
and no problems with water movements related, always doing focus carefully and softly (especially the 65x)

If anybody has doubts or questions about these objectives, don't hesitate to contact me.

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

#50 Post by patta » Fri Nov 26, 2021 4:25 am

Parenthesis, 2 late thoughts about original question, why those 60x 100x 250x dry

-empty magnification is sometimes useful; the eye or sensor are oversampling but that may help resolve the smallest details. I can see a little bit better tiny things with a 60x vs a 40x with same NA (or with a high mag eyepiece) just because details "look bigger".
In astronomy, full blow-up empty magnification is used routinely on "small" subjects like planets or double stars, where we want to squeeze any faint information hanging at the diffraction limit.
Back on microscope, changing the eyepieces, or the camera zoom, to get this higher mag may be an hassle; while rolling in a 100x dry may be simpler.

- aberrations scale with size; the smaller the objective is (hence shorter focal length, higher magnification) the smaller are its aberrations. They come from geometry, so depend on lens size.
Making an objective with NA 0.95 dry is though; but if it is small (high mag, like 100x) only few lenses are needed to get ok correction (aberrations smaller than NA theoretical resolution). So a 100x 0.95 is feasible at reasonable cost.
Instead think about a 10x 0.95 ! It has a huge field that must be corrected. Just scaling up the design of the 100x, won't work; the aberrations will get larger as well; too large, visible. It needs instead more sophisticate correction, read dozens of apochromatic lenses and huge barrels, like modern Planapos or litography objectives. And those many-lenses desings wouldn't work without all the modern antireflection coating stuff.
So 60x 0.85, 100x 0.95, are the oldest, simplest, cheapest way to get those NA.
While the silly "250x" may be indeed the best-corrected, most contrasty objective - in its narrow field.

Personal use: I hate high NA dry objectives; even the 40x 0.65! Water/oil otherwise
Recently got too a Lomo 30x water immersion, it become the go-to after 10x 0.25.

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