Stated magnification versus real magnification

Es gibt 56 Antworten in diesem Thema, welches 10.712 mal aufgerufen wurde. Der letzte Beitrag () ist von Steve_mt.

  • Hello,


    at least the Axiolab 5 is infinite, I guess all Axiolabs are. Strange enough that your older 100x objective did work, as it is for use with 160 mm tube length.

    On the foto your condensor seems fairly far down - usually the correct placement is nearly up to the highest possible point.


    all the best,

    Andreas

  • Hallo Steve,


    wir werden dir nicht helfen können. warum?

    - Du hast unendlich und endlich Objektive am gleichen Mikroskop!

    - Du zeigst uns immer nur Teile deines Mikroskops.

    - Wir wissen nicht, wie dein Mikroskop aussieht und welche Anbauteile du hast.

    - Wir wissen nicht, was für Okulare du hast.

    - Wir wissen nicht, was für eine Strichplatte du eingelegt hast. Es gibt verschiedene!

    - Wir wissen nicht, an welcher Position du die Strichplatte eingelegt hast.

    - Wir wissen nicht, welches Öl du verwendest und wie du es benutzt.


    So funktioniert das nicht.


    Ich habe an meinem Mikroskop gestestet. Wenn ich das 100x Objektiv benutze, dann habe ich mit Öl ein gutes Bild und den Umrechnungsfaktor 1:1. Ohne Öl habe ich ein sehr schlechtes Bild und immer noch 1:1 (identisch).


    Ich bin raus.


    Freundliche Grüße

    Peter

  • Hello,

    Would be nice if someone can test the same procedure and calibrate the measurements with oil and without oil for the x100 objective and see if there are same results. Because if one measures spores under oil immersion and applies a 1:1 scale, there might be some 15% error in the measurements!!!! --- or is it just me here with this anomaly ?!?!

    the measurements with the same objective are always the same, be it with oil or without. You only will get an unsharp and may be slightly distorted picture when you use an oil objective without oil - but the calibration will not be different.


    Even when using different objectiv models form different producers, usually that makes no difference. In my Olympus CH2 I have a normal dry 40x objectiv of Olympus and a Zeiss 40x oil objective - the calibration is the same for both.

    But if you use 160 objectives and infinite objectives in the wrong microscope model, than I could imagine that there is a difference. It is said that ininifinty microscopes even using objectives from an other producer may cause problems (with 160 microscopes there are no problems).

    I can test tomorrow and change my objectives of my infinite Olympus BX 40 to my 160 Olympus CH2 and look what is happening.


    best, Andreas

  • Hi folks,

    there is no need for testing: a mixture of infinite and 160mm lenses CANNOT work, it's like putting diesel in a regular gas car.


    It is the physical principle of the two different construction logics:

    In a 160mm microscope, the lenses in the objective create a beam with focus point at 160mm distance (not fully color corrected), and the ocular lense create a virtual image with color correction.


    In an infinite microscope, there is an additional lense in the micoscope body, creating a color corrected, strictly parallel beam, and the ocular lenses only magnify.


    If your microscope body is infinite, never use lenses without the ∞ sign.


    Wolfgang

  • So sorry for the confusion and enigmatic situation we have here, but now I understand that the problem is only mine :(

    Please note that I do not have any issue with the other objectives, only the x100 oil immersion ones.


    To start and solve the issue, the first question is whether my AxioLab RE is finite(160mm) or infinite. The non-oil objectives came with the microscope (great optics) and they have the infinity sign so


    [Q1] can we safely assume that the Axiolab RE is an infinite microscope??? I think so!


    Answers:


    Wolfgang says: If your microscope body is infinite, never use lenses without the ∞ sign.

    All my objectives have the ∞ sign. The old oil immersion is 160mm and not the one being tested. Maybe this model can't take x100 objectives?? I doubt it!


    Peter asks: You have infinite and finite objectives on the same microscope!

    And they all work well for a strange reason - but the one being tested has the infinity sign.


    - We don't know what your microscope looks like or what attachments you have. [Answer: link below]

    - We don't know what kind of eyepieces you have. [Answer: Zeiss E-PL10]

    - We don't know what kind of reticle you inserted. There are different! [Answer: Standard reticle eyepiece from eBay, I don't think it is the problem]

    - We don't know where you inserted the graticule. [Answer: Stage micrometre]

    - We don't know what oil you use and how you use it. [ Answer: Small drop oil on the stage micrometre and mount. No coverslip ]


    [Q2] If there is something wrong with the graticule, eyepieces, reticule.... would the symptom show also on the x630 and x400 objectives?


    What's left is the oil to blame perhaps! I don't know anything about its origin, but bought 50mls from Lab supplies who give it in a plastic container.


    Really lost now what's the problem??? The speculations of infinity eyepieces on finite microscope is not the issue.

    The microscope body is like this (objectives different but they are also with infinity sign):


    Carl Zeiss Trinocular Microscope Axiolab | eBay



    [Q3] Do you think that the oil-immersion objectives (∞) do not match my microscope ???

  • Let me write about the procedure, just in case... I mount the stage micrometer which has a very thin and small circular coverslip fixed to the glass slide, transfer a small drop of oil over its surface, mount, and bring to focus the scale. Then I place the reticule eyepiece (I have 3 of them) and align it so the zero marking is over the end of the stage marking. I count how many reticule markings make a known measurement and calibrate accordingly


    the x10 = x10um per reticule division (calculated magnification x 100)

    the x40 = x 2.51um per reticule division (calculated magnification x 398)

    the x63 = x 1.59um per reticule division (calculated magnification x 628)

    the x100 (no oil) x 1.05um per reticule division (calculated magnification x 960)

    the x100 (with oil) x 1.17um per reticule division (calculated magnification x 850)

  • Hello Steve,

    the x100 (no oil) x 1.05um per reticule decision (calculated magnification x 960)

    the x100 (with oil) x 1.17um per reticule decision (calculated magnification x 850)

    I have no idea how this can happen. Sorry to be of no help, but I have no declaration for this big difference.


    all the best,

    Andreas

  • the x100 (no oil) x 1.05um per reticule decision (calculated magnification x 960)

    the x100 (with oil) x 1.17um per reticule decision (calculated magnification x 850)

    How have you done this measurement ?

    1: test without oil : have you used a cover glas and water inbetween the measurement slide and the objective ?

    2: test with oil: have you used a cover glas and water inbetween the measuement slide and the objective ?


    This objectives are calculated for 0,17mm coverglas usage

    BR

    Uwe

  • Hallo Uwe,

    Wasser zwischen dem Mikrometerokular und dem Objektiv?! Und dazu noch Öl oder wie? Ich komme grad nicht so recht mit wie das gemeint ist.


    Dass die empfohlene Deckglasstärke 0,17 mm ist, stimmt schon. Andererseits benutzt jeder (aber auch wirklich jeder) Mykologen den ich kenne die wesentlich billigeren 0,13-0,17 mm Deckgläschchen - Du bestimmt auch - und ich habe noch nie von Problemen gehört. Kann mir nicht vorstellen, dass es daran liegt dass man solche Messunterschiede bekommt. Das dürfte höchstens Einfluss aufs Scharfstellen haben.


    beste Grüße,

    Andreas

  • Hallo Andreas

    Klar, die Dicke des Deckglases spielt keine grosse Rolle das ist klar aber es sollte halt auf jeden Fall eines benutzt werden.
    Ich kann mir vorstellen das es einen Unterschiedmacht ob man ohne Deckglas direkt auf das Objektmicrometer schaut oder mit Deckglas und Wasser zwischen Objektträger und Objektiv.
    Mein Vorschlag wäre es immer gleich zu machen wie man später auch praktisch mikroskopiert.

    Also in der Reihenfolge Objektträger , Wasser , Deckglas , Öl ( oder halt im Vergleich ohne Öl )

    Eventuell hat er ohne Deckglas das Öl direkt auf das Objekt Mikrometer gemacht.


    Gruss

    Uwe

  • without oil: Micrometer slide on stage, then no water no cover glass slip (direct visualization)

    with oil: Micrometer slide on stage, then droplet of oil on micrometer no cover glass (objective lens in oil)


    The micrometer already have a fixed coverslip I don't see why I have to put another one over it and water.




  • Hi Andreas

    He may have put the oil directly on the micrometer object without a cover slip.


    Greeting

    Uwe

    THAT WHAT I USED TO DO!!! when I get the 86 units per 100um (the wrong magnification!)


    Now I placed a coverslip over the micrometer fixed coverslip and oil over the second coverslip and I got 98:100. This was so sweaty to arrive to a solution of this mysetrious error. So now my calibrations a slightly screwed when I measured under the x100 but at least not by much (12% error).


    I cant understand the physics why a coverslip makes this difference ?!?!

  • Grüezi :)

    Some of the cheaper micrometers don´t have a coverslip, then you should use a separate one

    Ok, now im confused.

    I make all my measurements directly in the software of my microscope camera. During calibration, I had neither water nor a cover slip on the micrometer. When I read this thread I became afraid that all of my measurements I have ever taken could have been wrong. But I just checked, I always get the same readings, no matter whether with water and cover slip or without. If there is a difference at all, it is far below 1%.

    What I also don't get: If I understood correctly, he said that he only has the difference with the 100x lens. Shouldn't that occur with all lenses?



  • Hi everybody,


    @Steve, good news!

    But you still have a problem with your optics, probably the condensor is not adjusted. The lines of the eyepiece reticle have a blue shade towards the center, do you see that? And the lines of the reticle are still distorted to the corner, maybe you placed it the wrong way round (resulting in a wrong optical layer for the reticle).


    If you spend so much money for buying the best tools, you should also spend some more time to learn better how to use them.

    Also you should also spend a few Euro for oil with a guaranteed optimum refractory index, this might improve the results further.

    The newer Zeiss and Olympus lenses should have a correction factor very close to 1,000.


    ... and sell the useless 63x dry and buy a 40x oil instead ;)

    I cant understand the physics why a coverslip makes this difference ?!?!

    Air, water, glass and oil have different refractory indexes, causing the light beams to be bent at the borderlines. The objective is calculated for these effects to happen at a predefined distance, as stated on the lens.



    @Philipp:

    Die Fehler, ob mit dem richtigen Arbeitsabstand kalibriert wurde, treten vor allem bei sehr kleinen Arbeitsabständen auf. Und auch eher bei Objektiven, die auf die allerhöchste Auflösung getrimmt wurden (nA = 1,30).

    Aber der Wechsel der optischen Dichten von Wasser, Glas und Luft ist schon sehr wichtig für ein gutes Bild, beim 40x und vor allem beim 63x bekommt man ohne Wasser+Deckglas dazwischen die Skala gar nicht richtig scharf, das sollte man merken.


    Liebe Grüße,


    Wolfgang

  • Hallo Uwe

    ja, genau so mache ich das auch. Öltropfen direkt auf den Objektmikrometer. Auf die Idee, da erst noch einen Tropfen Flüssigkeit und ein Deckglas drauf zu legen bin ich noch gar nicht gekommen. Die mir zur Verfügung stehende Literatur sagt hierzu nichts.


    beste Grüße,

    Andreas

  • [...]


    ... and sell the useless 63x dry and buy a 40x oil instead ;)

    [...]

    PNF 40x/1,3 Oil: I love it!

    Like this ?


    Yes not very good optics the 630, I use it mostly for measurements (gives a bit more accurate results). I am not very fond of messing with oil, but maybe I should change mentality...


    Do you mean like this?


    Carl Zeiss Microscopy, LLC - Objective Assistant - Objective C Plan-Apochromat 40x/1.3 Oil DIC M27



    OMG!!! so expensive!!!!

  • Hello Uwe

    yes, that's exactly how I do it. Oil drops directly on the stage micrometer. The idea of putting a drop of liquid and a cover slip on top of it has never even occurred to me. The literature available to me says nothing about this.


    best regards,

    Andreas


    Hmmm.... for me that was the problem, so double check or can you confirm for us that u have no magnification error like what I reported ?

  • I think the problem is the camera method because I put my Canon G5X over the eyepiece and zoom a bit to fill the field. When I look with my eyes, I do not see the pincushion distortion. For the colour aberration, I see them but maybe I am not very touchy here, but in real life situation, they are not really significant or a big deal at that high magnification. Sometimes I turn the almost moncromatic photos to greyscale.


    Saying that, I do not know much about use of the condenser. I usually raise it until I have good contast. Too high I lose the contrast and result in getting a soft image, too down then I have too high contrast and blackened image. Usually, I test with my eye until I have rather good contrast and the blur washes away the background artefacts and dirt. I admit my setup is below average too :( :( - but for now that what I can afford. I miss a trinocular.

  • Saying that, I do not know much about use of the condenser. I usually raise it until I have good contast. Too high I lose the contrast and result in getting a soft image, too down then I have too high contrast and blackened image.

    Hi Steve,

    this is not how you should do it. Close the condensor blend if the image is too soft.


    To adjust the condensor in height, close the blend fully, use your smallest magnification, and lift the condensor until you see the border of the blend sharp and without color shades.


    At the end, it makes the difference wether you can see rough spores or not. Do you know someone with a standard diatomeae slide like Amphipleura pellucida, to check wether you see the finest structures with your current setting?


    compare pictures here


    There are so many people stating that fungal spores are smooth, because they don't know how to adjust their microscope...

    You have an excellent optical equipment, partially better than mine, it would be a shame not to use ist.

    I am not very fond of messing with oil, but maybe I should change mentality...

    ...yes, definitely!!! :)


    It's not messing, it is using the precision optics as designed.



    Wolfgang

  • Saying that, I do not know much about use of the condenser. I usually raise it until I have good contast. Too high I lose the contrast and result in getting a soft image, too down then I have too high contrast and blackened image.

    Hi Steve,

    this is not how you should do it. Close the condensor blend if the image is too soft.


    To adjust the condensor in height, close the blend fully, use your smallest magnification, and lift the condensor until you see the border of the blend sharp and without color shades.


    At the end, it makes the difference wether you can see rough spores or not. Do you know someone with a standard diatomeae permanent slide like Ampipleura pellucida, to check wether you see the finest structures with your current setting?


    This is how it should look:

    Amphipleura pellucida – Teil 2 – die maximale Auflösung


    There are so many people stating that fungal spores are smooth, because they don't know how to adjust their microscope... and your optical equipment is excellent - better than mine, it's a shame not to use it.



    Wolfgang